Materiały źródłowe

• #1 Overview of Basic Mechanisms of Cardiac Arrhythmia

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3164530/

  A cardiac arrhythmia simply defined is a variation from the normal heart rate and/or rhythm that is not physiologically justified. Recent years have witnessed important advances in our understanding of the electrophysiologic mechanisms underlying the development of a variety of cardiac arrhythmias. The mechanisms responsible for cardiac arrhythmias are generally divided into 2 major categories: (1) enhanced or abnormal impulse formation (ie, focal activity) and (2) conduction disturbances (ie, reentry). […] Abnormal automaticity includes both reduced automaticity, which causes bradycardia, and increased automaticity, which causes tachycardia. Arrhythmias caused by abnormal automaticity can result from diverse mechanisms. Alterations in sinus rate can be accompanied by shifts of the origin of the dominant pacemaker within the sinus node or to subsidiary pacemaker sites elsewhere in the atria. Impulse conduction out of the SA mode can be impaired or blocked as a result of disease or increased vagal activity leading to development of bradycardia. AV junctional rhythms occur when AV junctional pacemakers located either in the AV node or in the His bundle accelerate to exceed the rate of SA node, or when the SA nodal activation rate was too slow to suppress the AV junctional pacemaker.

• #2 Mechanisms of Cardiac Arrhythmias – Revista Española de Cardiología (English Edition)

  https://www.revespcardiol.org/en-mechanisms-cardiac-arrhythmias-articulo-S1885585711006086

  Cardiac arrhythmias are prevalent among humans across all age ranges and may occur in the setting of underlying heart disease as well as in structurally normal hearts. While arrhythmias are widely varied in their clinical presentations, they possess shared electrophysiologic properties at the cellular level. The 3 main mechanisms responsible for cardiac arrhythmias are automaticity, triggered activity, and reentry. Although identifying the specific mechanism may at times be challenging for the clinician and require invasive electrophysiologic study, differentiating and understanding the underlying mechanism may be critical to the development of an appropriate diagnosis and treatment strategy. […] Understanding the mechanisms of arrhythmias is helpful to the appropriate management and treatment of all arrhythmia types. Since the mechanisms that lead to clinical arrhythmias are frequently due to abnormalities beyond the tissue level, it is also essential to understand what occurs at the cellular level.

• #3 Mechanisms of Cardiac Arrhythmias – Revista Española de Cardiología (English Edition)

  https://www.revespcardiol.org/en-mechanisms-of-cardiac-arrhythmias-articulo-S1885585711006086

  Cardiac arrhythmias are prevalent among humans across all age ranges and may occur in the setting of underlying heart disease as well as in structurally normal hearts. While arrhythmias are widely varied in their clinical presentations, they possess shared electrophysiologic properties at the cellular level. The 3 main mechanisms responsible for cardiac arrhythmias are automaticity, triggered activity, and reentry. Although identifying the specific mechanism may at times be challenging for the clinician and require invasive electrophysiologic study, differentiating and understanding the underlying mechanism may be critical to the development of an appropriate diagnosis and treatment strategy. […] Understanding the mechanisms of arrhythmias is helpful to the appropriate management and treatment of all arrhythmia types. Since the mechanisms that lead to clinical arrhythmias are frequently due to abnormalities beyond the tissue level, it is also essential to understand what occurs at the cellular level.

• #4 Mechanisms of cardiac arrhythmias: from automaticity to re-entry (reentry) – The Cardiovascular

  https://ecgwaves.com/topic/mechanisms-cardiac-arrhythmias-automaticity-reentry-triggered-activity/

  Cardiac arrhythmias can be subdivided into the following categories: Bradyarrhythmias (bradycardia): arrhythmias commonly due to dysfunctional automaticity in pacemaker cells or blocking of impulses somewhere along the conduction system. Supraventricular tachyarrhythmias (tachycardia): rapid arrhythmias due to impulses originating from the atria. Ventricular tachyarrhythmias (tachycardia): rapid arrhythmias due to impulses originating from the ventricles. […] The mechanisms underlying cardiac arrhythmias are being unraveled at an accelerating pace, making arrhythmology a field of intense research activity. […] Arrhythmias arise if the impulse formation is abnormal, if the impulse transmission is abnormal, or if both these are abnormal. […] Abnormal impulse formation can cause arrhythmias by the following two mechanisms: Increased or abnormal automaticity, Triggered activity.

• #5 Mechanism of arrythmias | PPT

  https://www.slideshare.net/slideshow/mechanism-of-arrythmias/29637225

  1. Cardiac arrhythmias can be caused by disorders of impulse formation, disorders of impulse conduction, or a combination of the two. […] 2. Disorders of impulse formation include abnormalities in automaticity and triggered activity. […] 3. Abnormal automaticity occurs when an ectopic pacemaker fires at an inappropriate rate, taking over control of the heart rhythm from the normal sinus node. […] 4. Triggered activity is initiated by afterdepolarizations following an action potential. […] 5. Disorders of impulse conduction include conduction block and reentry, which is when an impulse circles back and reactivates tissue that is still recovering, leading to sustained, rapid rhythms. […] 6. The mechanisms responsible for arrhythmias are generally divided into Disorders of impulse formation, Disorders of impulse conduction, Combinations of both cardiac.

• #6 Overview of Basic Mechanisms of Cardiac Arrhythmia

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3164530/

  A cardiac arrhythmia simply defined is a variation from the normal heart rate and/or rhythm that is not physiologically justified. Recent years have witnessed important advances in our understanding of the electrophysiologic mechanisms underlying the development of a variety of cardiac arrhythmias. The mechanisms responsible for cardiac arrhythmias are generally divided into 2 major categories: (1) enhanced or abnormal impulse formation (ie, focal activity) and (2) conduction disturbances (ie, reentry). […] Abnormal automaticity includes both reduced automaticity, which causes bradycardia, and increased automaticity, which causes tachycardia. Arrhythmias caused by abnormal automaticity can result from diverse mechanisms. Alterations in sinus rate can be accompanied by shifts of the origin of the dominant pacemaker within the sinus node or to subsidiary pacemaker sites elsewhere in the atria. Impulse conduction out of the SA mode can be impaired or blocked as a result of disease or increased vagal activity leading to development of bradycardia. AV junctional rhythms occur when AV junctional pacemakers located either in the AV node or in the His bundle accelerate to exceed the rate of SA node, or when the SA nodal activation rate was too slow to suppress the AV junctional pacemaker.

• #7 Overview of Basic Mechanisms of Cardiac Arrhythmia

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3164530/

  Bradycardia can occur in structurally normal hearts because of genetic mutations that result in abnormalities of either membrane clock or Ca clock mechanisms of automaticity. One example is the mutation of hyperpolarization-activated nucleotide-gated channel (HCN4), which is part of the channels that carry If. Mutations of the HCN4 may cause familial bradycardia as well. […] Common diseases, such as heart failure and atrial fibrillation, may be associated with significant SA node dysfunction. Malfunction of both membrane voltage and Ca clocks might be associated with both of these common diseases. Zicha and colleagues reported that down-regulation of HCN4 expression contributes to heart failure-induced sinus node dysfunction. An A450 V missense loss of function mutation in HCN4 has recently been shown to underlie familial sinus bradycardia in several unrelated probands of Moroccan Jewish descent.

• #8 Mechanism of arrythmias | PPT

  https://www.slideshare.net/slideshow/mechanism-of-arrythmias/29637225

  1. Cardiac arrhythmias can be caused by disorders of impulse formation, disorders of impulse conduction, or a combination of the two. […] 2. Disorders of impulse formation include abnormalities in automaticity and triggered activity. […] 3. Abnormal automaticity occurs when an ectopic pacemaker fires at an inappropriate rate, taking over control of the heart rhythm from the normal sinus node. […] 4. Triggered activity is initiated by afterdepolarizations following an action potential. […] 5. Disorders of impulse conduction include conduction block and reentry, which is when an impulse circles back and reactivates tissue that is still recovering, leading to sustained, rapid rhythms. […] 6. The mechanisms responsible for arrhythmias are generally divided into Disorders of impulse formation, Disorders of impulse conduction, Combinations of both cardiac.

• #9 Mechanisms of Cardiac Arrhythmias – Revista Española de Cardiología (English Edition)

  https://www.revespcardiol.org/en-mechanisms-of-cardiac-arrhythmias-articulo-S1885585711006086

  The mechanisms responsible for cardiac arrhythmias may be divided into disorders of impulse formation, disorders of impulse conduction or a combination of both. […] The hallmark of normal automaticity is overdrive suppression. Overdriving a latent pacemaker cell faster than its intrinsic rate decreases the slope of phase 4, mediated mostly by enhanced activity of the Na/K exchange pump. […] An important distinction between enhanced normal and abnormal induced automaticity is that the latter is less sensitive to overdrive suppression, although there are situations where it may be observed. […] Triggered activity (TA) is defined by impulse initiation caused by afterdepolarizations (membrane potential oscillations that occur during or immediately following a preceding AP). […] A DAD is an oscillation in membrane voltage that occurs after completion of repolarization of the AP (during phase 4).

• #10 Mechanisms of Cardiac Arrhythmias – Revista Española de Cardiología (English Edition)

  https://www.revespcardiol.org/en-mechanisms-of-cardiac-arrhythmias-articulo-S1885585711006086

  The mechanisms responsible for cardiac arrhythmias may be divided into disorders of impulse formation, disorders of impulse conduction or a combination of both. […] The hallmark of normal automaticity is overdrive suppression. Overdriving a latent pacemaker cell faster than its intrinsic rate decreases the slope of phase 4, mediated mostly by enhanced activity of the Na/K exchange pump. […] An important distinction between enhanced normal and abnormal induced automaticity is that the latter is less sensitive to overdrive suppression, although there are situations where it may be observed. […] Triggered activity (TA) is defined by impulse initiation caused by afterdepolarizations (membrane potential oscillations that occur during or immediately following a preceding AP). […] A DAD is an oscillation in membrane voltage that occurs after completion of repolarization of the AP (during phase 4).

• #11 Mechanisms of Cardiac Arrhythmias – Revista Española de Cardiología (English Edition)

  https://www.revespcardiol.org/en-mechanisms-cardiac-arrhythmias-articulo-S1885585711006086

  Abnormal automaticity is thought to play a role in cases of elevated extracellular potassium, low intracellular pH, and catecholamine excess. […] Triggered activity (TA) is defined by impulse initiation caused by afterdepolarizations (membrane potential oscillations that occur during or immediately following a preceding AP). […] Delayed Afterdepolarization-Induced Triggered Activity is an oscillation in membrane voltage that occurs after completion of repolarization of the AP (during phase 4). […] Early afterdepolarization-triggered arrhythmias are rate dependent, and in general the EAD amplitude increases at a slow rate. […] Reentry has been divided in 2 main groups: anatomical or classic reentry, where the circuit is determined by anatomical structures, and functional reentry, which in turn includes different mechanisms.

• #12 Mechanisms of Cardiac Arrhythmias – Revista Española de Cardiología (English Edition)

  https://www.revespcardiol.org/en-mechanisms-cardiac-arrhythmias-articulo-S1885585711006086

  Abnormal automaticity is thought to play a role in cases of elevated extracellular potassium, low intracellular pH, and catecholamine excess. […] Triggered activity (TA) is defined by impulse initiation caused by afterdepolarizations (membrane potential oscillations that occur during or immediately following a preceding AP). […] Delayed Afterdepolarization-Induced Triggered Activity is an oscillation in membrane voltage that occurs after completion of repolarization of the AP (during phase 4). […] Early afterdepolarization-triggered arrhythmias are rate dependent, and in general the EAD amplitude increases at a slow rate. […] Reentry has been divided in 2 main groups: anatomical or classic reentry, where the circuit is determined by anatomical structures, and functional reentry, which in turn includes different mechanisms.

• #13 Mechanism of arrythmias | PPT

  https://www.slideshare.net/slideshow/mechanism-of-arrythmias/29637225

  7. Automaticity is the property of a fiber to initiate an impulse spontaneously, without need for prior stimulation. […] 8. Ectopic pacemakers are usually suppressed by overdrive suppression by the more rapidly firing SA node or by concealed conduction from neighboring fibers. […] 9. Triggered activity is initiated by after-depolarizations, which are depolarizing oscillations in membrane voltage induced by one or more preceding action potentials. […] 10. Early after-depolarizations (EADs), arise from a reduced level of membrane potential during phases 2 and 3 of the cardiac action potential. […] 11. Late or delayed after-depolarizations (DADs), occur after completion of repolarization, generally at a more negative membrane potential than that from which EADs arise. […] 12. Disorder of Impulse Conduction can be conduction block or re-entry. […] 13. Atrial flutter is caused by a large reentrant circuit in the wall of the right atrium. […] 14. Atrial fibrillation is caused by numerous wavelets of depolarization spreading throughout the atria simultaneously, leading to an absence of coordinated atrial contraction.

• #14 Mechanisms of Cardiac Arrhythmias – Revista Española de Cardiología (English Edition)

  https://www.revespcardiol.org/en-mechanisms-of-cardiac-arrhythmias-articulo-S1885585711006086

  The mechanisms responsible for cardiac arrhythmias may be divided into disorders of impulse formation, disorders of impulse conduction or a combination of both. […] The hallmark of normal automaticity is overdrive suppression. Overdriving a latent pacemaker cell faster than its intrinsic rate decreases the slope of phase 4, mediated mostly by enhanced activity of the Na/K exchange pump. […] An important distinction between enhanced normal and abnormal induced automaticity is that the latter is less sensitive to overdrive suppression, although there are situations where it may be observed. […] Triggered activity (TA) is defined by impulse initiation caused by afterdepolarizations (membrane potential oscillations that occur during or immediately following a preceding AP). […] A DAD is an oscillation in membrane voltage that occurs after completion of repolarization of the AP (during phase 4).

• #15 Overview of Basic Mechanisms of Cardiac Arrhythmia

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3164530/

  EADs are typically observed in cardiac tissues exposed to injury, altered electrolytes, hypoxia, acidosis, catecholamines, and pharmacologic agents, including antiarrhythmic drugs. Ventricular hypertrophy and heart failure also predispose to the development of EADs. EAD characteristics vary as a function of animal species, tissue or cell type, and the method by which the EAD is elicited. Although specific mechanisms of EAD induction can differ, a critical prolongation of repolarization accompanies most, but not all, EADs. Drugs that inhibit potassium currents or which augment inward currents predispose to the development of EADs. […] An example of DAD-induced arrhythmia is the catecholaminergic polymorphic ventricular tachycardia (CPVT), which may be caused by the mutation of either the type 2 ryanodine receptor (RyR2) or the calsequestrin (CSQ2). The principal mechanism underlying these arrhythmias is the leaky ryanodine receptor, which is aggravated during catecholamine stimulation. A typical clinical phenotype of CPVT is bidirectional ventricular tachycardia, which is also seen in digitalis toxicity.

• #16 Overview of Basic Mechanisms of Cardiac Arrhythmia

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3164530/

  EADs are typically observed in cardiac tissues exposed to injury, altered electrolytes, hypoxia, acidosis, catecholamines, and pharmacologic agents, including antiarrhythmic drugs. Ventricular hypertrophy and heart failure also predispose to the development of EADs. EAD characteristics vary as a function of animal species, tissue or cell type, and the method by which the EAD is elicited. Although specific mechanisms of EAD induction can differ, a critical prolongation of repolarization accompanies most, but not all, EADs. Drugs that inhibit potassium currents or which augment inward currents predispose to the development of EADs. […] An example of DAD-induced arrhythmia is the catecholaminergic polymorphic ventricular tachycardia (CPVT), which may be caused by the mutation of either the type 2 ryanodine receptor (RyR2) or the calsequestrin (CSQ2). The principal mechanism underlying these arrhythmias is the leaky ryanodine receptor, which is aggravated during catecholamine stimulation. A typical clinical phenotype of CPVT is bidirectional ventricular tachycardia, which is also seen in digitalis toxicity.

• #17 Mechanisms of Cardiac Arrhythmias – Revista Española de Cardiología (English Edition)

  https://www.revespcardiol.org/en-mechanisms-of-cardiac-arrhythmias-articulo-S1885585711006086

  The EADs are oscillatory potentials that occur during the AP plateau (phase 2 EADs) or during the late repolarization (phase 3 EADs). […] Reentry has been divided in 2 main groups: anatomical or classic reentry, where the circuit is determined by anatomical structures, and functional reentry, which in turn includes different mechanisms. […] Prerequisites for reentry include: A substrate: the presence of joined myocardial tissue with different electrophysiological properties, conduction, and refractoriness. […] The classic reentry mechanism is based on an inexcitable anatomical obstacle surrounded by a circular pathway in which the wavefront can reenter, creating fixed and stable reentrant circuits. […] In functional reentry, the circuit is not determined by anatomic obstacles; it is defined by dynamic heterogeneities in the electrophysiologic properties of the involving tissue. […] The predominant mechanisms underlying most VTs are abnormal automaticity, TA, and reentry. The latter is the most frequent mechanism causing VT.

• #18 Overview of Basic Mechanisms of Cardiac Arrhythmia

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3164530/

  EADs are typically observed in cardiac tissues exposed to injury, altered electrolytes, hypoxia, acidosis, catecholamines, and pharmacologic agents, including antiarrhythmic drugs. Ventricular hypertrophy and heart failure also predispose to the development of EADs. EAD characteristics vary as a function of animal species, tissue or cell type, and the method by which the EAD is elicited. Although specific mechanisms of EAD induction can differ, a critical prolongation of repolarization accompanies most, but not all, EADs. Drugs that inhibit potassium currents or which augment inward currents predispose to the development of EADs. […] An example of DAD-induced arrhythmia is the catecholaminergic polymorphic ventricular tachycardia (CPVT), which may be caused by the mutation of either the type 2 ryanodine receptor (RyR2) or the calsequestrin (CSQ2). The principal mechanism underlying these arrhythmias is the leaky ryanodine receptor, which is aggravated during catecholamine stimulation. A typical clinical phenotype of CPVT is bidirectional ventricular tachycardia, which is also seen in digitalis toxicity.

• #19 Overview of Basic Mechanisms of Cardiac Arrhythmia

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3164530/

  EADs are typically observed in cardiac tissues exposed to injury, altered electrolytes, hypoxia, acidosis, catecholamines, and pharmacologic agents, including antiarrhythmic drugs. Ventricular hypertrophy and heart failure also predispose to the development of EADs. EAD characteristics vary as a function of animal species, tissue or cell type, and the method by which the EAD is elicited. Although specific mechanisms of EAD induction can differ, a critical prolongation of repolarization accompanies most, but not all, EADs. Drugs that inhibit potassium currents or which augment inward currents predispose to the development of EADs. […] An example of DAD-induced arrhythmia is the catecholaminergic polymorphic ventricular tachycardia (CPVT), which may be caused by the mutation of either the type 2 ryanodine receptor (RyR2) or the calsequestrin (CSQ2). The principal mechanism underlying these arrhythmias is the leaky ryanodine receptor, which is aggravated during catecholamine stimulation. A typical clinical phenotype of CPVT is bidirectional ventricular tachycardia, which is also seen in digitalis toxicity.

• #20 Overview of Basic Mechanisms of Cardiac Arrhythmia

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3164530/

  In 2003, Burashnikov and Antzelevitch described a novel mechanism giving rise to triggered activity, termed late phase 3 EAD, which combines properties of both EAD and DAD, but has its own unique character. Late phase 3 EAD-induced triggered extrasystoles represent a new concept of arrhythmogenesis in which abbreviated repolarization permits normal SR calcium release to induce an EAD-mediated closely coupled triggered response, particularly under conditions permitting intracellular calcium loading. […] Reentry is fundamentally different from automaticity or triggered activity in the mechanism by which it initiates and sustains cardiac arrhythmias. Circus movement reentry occurs when an activation wavefront propagates around an anatomic or functional obstacle or core, and reexcites the site of origin. In this type of reentry, all cells take turns in recovering from excitation so that they are ready to be excited again when the next wavefront arrives. […] The mechanisms of arrhythmogenesis in BrS can be explained by the heterogeneous shortening of the APD on the right ventricular epicardium.

• #21 Overview of Basic Mechanisms of Cardiac Arrhythmia

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3164530/

  In 2003, Burashnikov and Antzelevitch described a novel mechanism giving rise to triggered activity, termed late phase 3 EAD, which combines properties of both EAD and DAD, but has its own unique character. Late phase 3 EAD-induced triggered extrasystoles represent a new concept of arrhythmogenesis in which abbreviated repolarization permits normal SR calcium release to induce an EAD-mediated closely coupled triggered response, particularly under conditions permitting intracellular calcium loading. […] Reentry is fundamentally different from automaticity or triggered activity in the mechanism by which it initiates and sustains cardiac arrhythmias. Circus movement reentry occurs when an activation wavefront propagates around an anatomic or functional obstacle or core, and reexcites the site of origin. In this type of reentry, all cells take turns in recovering from excitation so that they are ready to be excited again when the next wavefront arrives. […] The mechanisms of arrhythmogenesis in BrS can be explained by the heterogeneous shortening of the APD on the right ventricular epicardium.

• #22 Cardiac arrhythmias pathophysiology | PPT

  https://www.slideshare.net/slideshow/cardiac-arrhythmias-pathophysiology/237187702

  Conversely, there may be enhanced automaticity of SA node leading to sinus tachycardia. […] Triggered activity (or after-depolarization) occur when a normal AP triggers extra-abnormal depolarisations. […] Two major forms of triggered rhythms are recognised: „delayed after-depolarization (DAD)” „early after-depolarisation (EAD)”. […] The third type of electrical disturbance of the heart involves defects in impulse conduction which can result from either one or combination of any of the three mechanisms: (a) conduction block, (b) re-entry phenomenon and (c) accessory tract pathways. […] It has been estimated that 80 to 90% of Clinical arrhythmias occur due to re entry phenomenon. […] In these patients an accessory atrioventricular pathway (a sort of bypass tract called bundle of Kent) is present.

• #23 Mechanisms of Cardiac Arrhythmias – Revista Española de Cardiología (English Edition)

  https://www.revespcardiol.org/en-mechanisms-cardiac-arrhythmias-articulo-S1885585711006086

  Abnormal automaticity is thought to play a role in cases of elevated extracellular potassium, low intracellular pH, and catecholamine excess. […] Triggered activity (TA) is defined by impulse initiation caused by afterdepolarizations (membrane potential oscillations that occur during or immediately following a preceding AP). […] Delayed Afterdepolarization-Induced Triggered Activity is an oscillation in membrane voltage that occurs after completion of repolarization of the AP (during phase 4). […] Early afterdepolarization-triggered arrhythmias are rate dependent, and in general the EAD amplitude increases at a slow rate. […] Reentry has been divided in 2 main groups: anatomical or classic reentry, where the circuit is determined by anatomical structures, and functional reentry, which in turn includes different mechanisms.

• #24 Mechanisms of Cardiac Arrhythmias – Revista Española de Cardiología (English Edition)

  https://www.revespcardiol.org/en-mechanisms-of-cardiac-arrhythmias-articulo-S1885585711006086

  The EADs are oscillatory potentials that occur during the AP plateau (phase 2 EADs) or during the late repolarization (phase 3 EADs). […] Reentry has been divided in 2 main groups: anatomical or classic reentry, where the circuit is determined by anatomical structures, and functional reentry, which in turn includes different mechanisms. […] Prerequisites for reentry include: A substrate: the presence of joined myocardial tissue with different electrophysiological properties, conduction, and refractoriness. […] The classic reentry mechanism is based on an inexcitable anatomical obstacle surrounded by a circular pathway in which the wavefront can reenter, creating fixed and stable reentrant circuits. […] In functional reentry, the circuit is not determined by anatomic obstacles; it is defined by dynamic heterogeneities in the electrophysiologic properties of the involving tissue. […] The predominant mechanisms underlying most VTs are abnormal automaticity, TA, and reentry. The latter is the most frequent mechanism causing VT.

• #25 Mechanisms of Cardiac Arrhythmias – Revista Española de Cardiología (English Edition)

  https://www.revespcardiol.org/en-mechanisms-cardiac-arrhythmias-articulo-S1885585711006086

  Abnormal automaticity is thought to play a role in cases of elevated extracellular potassium, low intracellular pH, and catecholamine excess. […] Triggered activity (TA) is defined by impulse initiation caused by afterdepolarizations (membrane potential oscillations that occur during or immediately following a preceding AP). […] Delayed Afterdepolarization-Induced Triggered Activity is an oscillation in membrane voltage that occurs after completion of repolarization of the AP (during phase 4). […] Early afterdepolarization-triggered arrhythmias are rate dependent, and in general the EAD amplitude increases at a slow rate. […] Reentry has been divided in 2 main groups: anatomical or classic reentry, where the circuit is determined by anatomical structures, and functional reentry, which in turn includes different mechanisms.

• #26 Mechanisms of Cardiac Arrhythmias – Revista Española de Cardiología (English Edition)

  https://www.revespcardiol.org/en-mechanisms-of-cardiac-arrhythmias-articulo-S1885585711006086

  The EADs are oscillatory potentials that occur during the AP plateau (phase 2 EADs) or during the late repolarization (phase 3 EADs). […] Reentry has been divided in 2 main groups: anatomical or classic reentry, where the circuit is determined by anatomical structures, and functional reentry, which in turn includes different mechanisms. […] Prerequisites for reentry include: A substrate: the presence of joined myocardial tissue with different electrophysiological properties, conduction, and refractoriness. […] The classic reentry mechanism is based on an inexcitable anatomical obstacle surrounded by a circular pathway in which the wavefront can reenter, creating fixed and stable reentrant circuits. […] In functional reentry, the circuit is not determined by anatomic obstacles; it is defined by dynamic heterogeneities in the electrophysiologic properties of the involving tissue. […] The predominant mechanisms underlying most VTs are abnormal automaticity, TA, and reentry. The latter is the most frequent mechanism causing VT.

• #27 Mechanisms of Cardiac Arrhythmias – Revista Española de Cardiología (English Edition)

  https://www.revespcardiol.org/en-mechanisms-cardiac-arrhythmias-articulo-S1885585711006086

  Prerequisites for reentry include: A substrate: the presence of joined myocardial tissue with different electrophysiological properties, conduction, and refractoriness. […] The classic reentry mechanism is based on an inexcitable anatomical obstacle surrounded by a circular pathway in which the wavefront can reenter, creating fixed and stable reentrant circuits. […] Clinical examples: AV reentrant tachycardia associated with a bypass tract, AV nodal reentrant tachycardia, atrial flutter, bundle branch reentry VT, post-infarction VT. […] The predominant mechanisms underlying most VTs are abnormal automaticity, TA, and reentry. The latter is the most frequent mechanism causing VT.

• #28 Mechanisms of Cardiac Arrhythmias – Revista Española de Cardiología (English Edition)

  https://www.revespcardiol.org/en-mechanisms-of-cardiac-arrhythmias-articulo-S1885585711006086

  The EADs are oscillatory potentials that occur during the AP plateau (phase 2 EADs) or during the late repolarization (phase 3 EADs). […] Reentry has been divided in 2 main groups: anatomical or classic reentry, where the circuit is determined by anatomical structures, and functional reentry, which in turn includes different mechanisms. […] Prerequisites for reentry include: A substrate: the presence of joined myocardial tissue with different electrophysiological properties, conduction, and refractoriness. […] The classic reentry mechanism is based on an inexcitable anatomical obstacle surrounded by a circular pathway in which the wavefront can reenter, creating fixed and stable reentrant circuits. […] In functional reentry, the circuit is not determined by anatomic obstacles; it is defined by dynamic heterogeneities in the electrophysiologic properties of the involving tissue. […] The predominant mechanisms underlying most VTs are abnormal automaticity, TA, and reentry. The latter is the most frequent mechanism causing VT.

• #29 Mechanisms of Cardiac Arrhythmias – Revista Española de Cardiología (English Edition)

  https://www.revespcardiol.org/en-mechanisms-cardiac-arrhythmias-articulo-S1885585711006086

  Prerequisites for reentry include: A substrate: the presence of joined myocardial tissue with different electrophysiological properties, conduction, and refractoriness. […] The classic reentry mechanism is based on an inexcitable anatomical obstacle surrounded by a circular pathway in which the wavefront can reenter, creating fixed and stable reentrant circuits. […] Clinical examples: AV reentrant tachycardia associated with a bypass tract, AV nodal reentrant tachycardia, atrial flutter, bundle branch reentry VT, post-infarction VT. […] The predominant mechanisms underlying most VTs are abnormal automaticity, TA, and reentry. The latter is the most frequent mechanism causing VT.

• #30 Mechanisms of Cardiac Arrhythmias – Revista Española de Cardiología (English Edition)

  https://www.revespcardiol.org/en-mechanisms-of-cardiac-arrhythmias-articulo-S1885585711006086

  The EADs are oscillatory potentials that occur during the AP plateau (phase 2 EADs) or during the late repolarization (phase 3 EADs). […] Reentry has been divided in 2 main groups: anatomical or classic reentry, where the circuit is determined by anatomical structures, and functional reentry, which in turn includes different mechanisms. […] Prerequisites for reentry include: A substrate: the presence of joined myocardial tissue with different electrophysiological properties, conduction, and refractoriness. […] The classic reentry mechanism is based on an inexcitable anatomical obstacle surrounded by a circular pathway in which the wavefront can reenter, creating fixed and stable reentrant circuits. […] In functional reentry, the circuit is not determined by anatomic obstacles; it is defined by dynamic heterogeneities in the electrophysiologic properties of the involving tissue. […] The predominant mechanisms underlying most VTs are abnormal automaticity, TA, and reentry. The latter is the most frequent mechanism causing VT.

• #31 Overview of Arrhythmias – Cardiovascular Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/cardiovascular-disorders/overview-of-arrhythmias-and-conduction-disorders/overview-of-arrhythmias

  Under certain conditions, typically precipitated by a premature beat, reentry can cause continuous circulation of an activation wavefront, causing a tachyarrhythmia. […] However, 3 conditions favor reentry: Shortening of tissue refractoriness (eg, by sympathetic stimulation), Lengthening of the conduction pathway (eg, by hypertrophy or abnormal conduction pathways), Slowing of impulse conduction (eg, by ischemia).

• #32 Atrial fibrillation | Nature Reviews Disease Primers

  https://www.nature.com/articles/s41572-022-00347-9

  Atrial fibrillation (AF) is the most common cardiac arrhythmia despite substantial efforts to understand the pathophysiology of the condition and develop improved treatments. […] Research has revealed that defects in specific molecular pathways underlie AF pathogenesis, resulting in electrical conduction disorders that drive AF. […] The severity of this so-called electropathology correlates with the stage of AF disease progression and determines the response to AF treatment. […] Therefore, unravelling the molecular mechanisms underlying electropathology is expected to fuel the development of innovative personalized diagnostic tools and mechanism-based therapies. […] Currently, various treatment modalities targeting AF-related electropathology, including lifestyle changes, pharmaceutical and nutraceutical therapy, substrate-based ablative therapy, and neuromodulation, are available to maintain sinus rhythm and might offer a novel holistic strategy to treat AF.

• #33 Electrolyte’s imbalance role in atrial fibrillation: Pharmacological management | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-022-00065-z

  The contribution of the perpetuation of atrial fibrillation is caused by electrical remodeling in which calcium, sodium and potassium channels could refer to changes in the ion channel protein expression, development of fibrosis, gene transcription and ion channel redistribution. […] Calcium and magnesium could influence the risk of atrial fibrillation which is the leading cause of cardiac death, heart failure and ischemic stroke. […] The elevated serum concentration of calcium had a higher range of in-patients mortality, increased total cost of hospitalization and increased length of hospital stay as compared to those without hypercalcemia in atrial fibrillation patients. […] Moreover, chloride channels could affect homeostasis, atrial myocardial metabolism which may participate in the development of atrial fibrillation.

• #34 Electrolyte’s imbalance role in atrial fibrillation: Pharmacological management | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-022-00065-z

  The contribution of the perpetuation of atrial fibrillation is caused by electrical remodeling in which calcium, sodium and potassium channels could refer to changes in the ion channel protein expression, development of fibrosis, gene transcription and ion channel redistribution. […] Calcium and magnesium could influence the risk of atrial fibrillation which is the leading cause of cardiac death, heart failure and ischemic stroke. […] The elevated serum concentration of calcium had a higher range of in-patients mortality, increased total cost of hospitalization and increased length of hospital stay as compared to those without hypercalcemia in atrial fibrillation patients. […] Moreover, chloride channels could affect homeostasis, atrial myocardial metabolism which may participate in the development of atrial fibrillation.

• #35 Electrolyte’s imbalance role in atrial fibrillation: Pharmacological management | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-022-00065-z

  Up to a 50% risk of incidence of AF are higher in which left ventricular hypertrophy, sudden cardiovascular death and overall mortality relate to a low serum magnesium level. […] Additionally, magnesium prevents the occurrence of AF after cardiac surgery, whereas greater levels of serum phosphorus in the large population-based study and the related calciumphosphorus products were linked with a greater incidence of AF. […] Numerous clinical studies had shown the high preoperative risk of AF that is linked with lower serum potassium levels. […] The conventional risk factor of increased risk of new onset of AF events could independently link with high dietary sodium intake which enhances the fibrosis and inflammation in the atrium but the mechanism remains unknown. […] This review concludes that electrolytes imbalance plays a significant role in the pathogenesis of atrial fibrillation.

• #36 Electrolyte’s imbalance role in atrial fibrillation: Pharmacological management | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-022-00065-z

  Up to a 50% risk of incidence of AF are higher in which left ventricular hypertrophy, sudden cardiovascular death and overall mortality relate to a low serum magnesium level. […] Additionally, magnesium prevents the occurrence of AF after cardiac surgery, whereas greater levels of serum phosphorus in the large population-based study and the related calciumphosphorus products were linked with a greater incidence of AF. […] Numerous clinical studies had shown the high preoperative risk of AF that is linked with lower serum potassium levels. […] The conventional risk factor of increased risk of new onset of AF events could independently link with high dietary sodium intake which enhances the fibrosis and inflammation in the atrium but the mechanism remains unknown. […] This review concludes that electrolytes imbalance plays a significant role in the pathogenesis of atrial fibrillation.

• #37 Electrolyte’s imbalance role in atrial fibrillation: Pharmacological management | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-022-00065-z

  Up to a 50% risk of incidence of AF are higher in which left ventricular hypertrophy, sudden cardiovascular death and overall mortality relate to a low serum magnesium level. […] Additionally, magnesium prevents the occurrence of AF after cardiac surgery, whereas greater levels of serum phosphorus in the large population-based study and the related calciumphosphorus products were linked with a greater incidence of AF. […] Numerous clinical studies had shown the high preoperative risk of AF that is linked with lower serum potassium levels. […] The conventional risk factor of increased risk of new onset of AF events could independently link with high dietary sodium intake which enhances the fibrosis and inflammation in the atrium but the mechanism remains unknown. […] This review concludes that electrolytes imbalance plays a significant role in the pathogenesis of atrial fibrillation.

• #38

  https://journals.lww.com/bjem/fulltext/2023/02030/a_review_of_arrhythmias_in_endocrinology.3.aspx

  Potassium imbalance is a major problem in diabetic ketoacidosis and can potentially lead to deadly arrhythmias. […] Certain anti-diabetic drugs may cause QT prolongation, either as a result of the drugs effect of hypoglycemia or as a direct side effect. […] Hypothyroidism can lead to a reduction in cardiac output of up to 30%40%, which can be attributed to a decrease in both stroke volume and heart rate. Additionally, hypothyroidism can cause varying degrees of conduction blocks. […] Most rhythm and conduction abnormalities identified in hypothyroidism can be quickly resolved with the start of levothyroxine medication in the proper dosage. […] In hypothyroidism, the expression of hepatic low-density lipoprotein receptors declines, which results in decreased cholesterol clearance and the development of hyperlipidemia.

• #39 Electrolyte’s imbalance role in atrial fibrillation: Pharmacological management | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-022-00065-z

  Up to a 50% risk of incidence of AF are higher in which left ventricular hypertrophy, sudden cardiovascular death and overall mortality relate to a low serum magnesium level. […] Additionally, magnesium prevents the occurrence of AF after cardiac surgery, whereas greater levels of serum phosphorus in the large population-based study and the related calciumphosphorus products were linked with a greater incidence of AF. […] Numerous clinical studies had shown the high preoperative risk of AF that is linked with lower serum potassium levels. […] The conventional risk factor of increased risk of new onset of AF events could independently link with high dietary sodium intake which enhances the fibrosis and inflammation in the atrium but the mechanism remains unknown. […] This review concludes that electrolytes imbalance plays a significant role in the pathogenesis of atrial fibrillation.

• #40 Atrial fibrillation | Nature Reviews Disease Primers

  https://www.nature.com/articles/s41572-022-00347-9

  Atrial fibrillation (AF) is the most common cardiac arrhythmia despite substantial efforts to understand the pathophysiology of the condition and develop improved treatments. […] Research has revealed that defects in specific molecular pathways underlie AF pathogenesis, resulting in electrical conduction disorders that drive AF. […] The severity of this so-called electropathology correlates with the stage of AF disease progression and determines the response to AF treatment. […] Therefore, unravelling the molecular mechanisms underlying electropathology is expected to fuel the development of innovative personalized diagnostic tools and mechanism-based therapies. […] Currently, various treatment modalities targeting AF-related electropathology, including lifestyle changes, pharmaceutical and nutraceutical therapy, substrate-based ablative therapy, and neuromodulation, are available to maintain sinus rhythm and might offer a novel holistic strategy to treat AF.

• #41 Electrolyte’s imbalance role in atrial fibrillation: Pharmacological management | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-022-00065-z

  The contribution of the perpetuation of atrial fibrillation is caused by electrical remodeling in which calcium, sodium and potassium channels could refer to changes in the ion channel protein expression, development of fibrosis, gene transcription and ion channel redistribution. […] Calcium and magnesium could influence the risk of atrial fibrillation which is the leading cause of cardiac death, heart failure and ischemic stroke. […] The elevated serum concentration of calcium had a higher range of in-patients mortality, increased total cost of hospitalization and increased length of hospital stay as compared to those without hypercalcemia in atrial fibrillation patients. […] Moreover, chloride channels could affect homeostasis, atrial myocardial metabolism which may participate in the development of atrial fibrillation.

• #42 Atrial fibrillation – Wikipedia

  https://en.wikipedia.org/wiki/Atrial_fibrillation

  An important theory is that the regular impulses produced by the sinus node for a normal heartbeat are overwhelmed by rapid electrical discharges produced in the atria and adjacent parts of the pulmonary veins. […] In a heart with AF, the increased calcium release from the sarcoplasmic reticulum and increased calcium sensitivity can lead to an accumulation of intracellular calcium and causes downregulation of L-type calcium channels. This reduces the duration of action potential and the refractory period, thus favoring the conduction of re-entrant waves.

• #43 New mechanism discovered for the life-threatening arrhythmias in Andersen-Tawil syndrome | EurekAlert!

  https://www.eurekalert.org/news-releases/1040441

  The study, published in Circulation Research, establishes a direct link between these life-threatening arrhythmias and the C122Y mutation in the Kir2.1 potassium channel. […] The study demonstrates that a specific genetic mutation (C122Y) in the Kir2.1 potassium channel alters the function not only of Kir2.1 but also of the main cardiac sodium channel NaV1.5, thus establishing a direct link with the life-threatening arrhythmias associated with ATS1. […] The study reveals that the C122Y mutation in Kir2.1 has a dual effect: it causes a reorganization of the Kir2.1 channel that destabilizes its binding to the phospholipid PIP2, a key lipid-signaling component of the cell membrane, and also disrupts the expression of the protein that forms the NaV1.5 channel, impairing its function. […] Dr. Jalife underscored the importance of the interaction between these channels for cardiac health, explaining that any alteration that disturbs the function of one or both channels can trigger life-threatening arrhythmias.

• #44 Mechanism of arrythmias | PPT

  https://www.slideshare.net/slideshow/mechanism-of-arrythmias/29637225

  7. Automaticity is the property of a fiber to initiate an impulse spontaneously, without need for prior stimulation. […] 8. Ectopic pacemakers are usually suppressed by overdrive suppression by the more rapidly firing SA node or by concealed conduction from neighboring fibers. […] 9. Triggered activity is initiated by after-depolarizations, which are depolarizing oscillations in membrane voltage induced by one or more preceding action potentials. […] 10. Early after-depolarizations (EADs), arise from a reduced level of membrane potential during phases 2 and 3 of the cardiac action potential. […] 11. Late or delayed after-depolarizations (DADs), occur after completion of repolarization, generally at a more negative membrane potential than that from which EADs arise. […] 12. Disorder of Impulse Conduction can be conduction block or re-entry. […] 13. Atrial flutter is caused by a large reentrant circuit in the wall of the right atrium. […] 14. Atrial fibrillation is caused by numerous wavelets of depolarization spreading throughout the atria simultaneously, leading to an absence of coordinated atrial contraction.

• #45 Arrhythmias – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK558923/

  Mechanism: Accessory pathway present outside of the AV node-Bundle of Kent. […] Mechanism: Slow fast fibers present in AV node peri-nodal tissue leading to re-entry. […] Mechanism: Multiple reentrant wavelets due to atrial ectopy from muscle fibers near the proximal part of the pulmonary vein. […] Mechanism: Presence of damaged fibers in ischemic heart disease leading to re-entry of current leading to disorganized high-frequency excitation. […] Mechanism: It is usually precipitated by premature ventricular contraction leading to the R on T phenomenon. […] Bradyarrhythmia is defined as a heart rate below 60 beats per minute (bpm) and comprises several rhythm disorders, including atrioventricular (A-V) blocks and sinus node disorders. […] Mechanism: Atrial impulses are conducted with a delay or not at all when an electrical impulse reaches a tissue that not excitable or is in a refractory period. […] Mechanism: Senescence of the SA node, an ischemic event involving the SA node leading to impulse generation at a slower rate. […] Mechanism: Subaortic outflow tract obstruction from abnormal hypertrophy of the septal region of the heart, leading to precipitation of ventricular arrhythmias.

• #46 Overview of Arrhythmias – Cardiovascular Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/cardiovascular-disorders/overview-of-arrhythmias-and-conduction-disorders/overview-of-arrhythmias

  The heart beats in a regular, coordinated way because electrical impulses generated and spread by myocytes with unique electrical properties trigger a sequence of organized myocardial contractions. Arrhythmias and conduction disorders are caused by abnormalities in the generation or conduction of these electrical impulses or both. […] Rhythm disturbances result from abnormalities of impulse formation, impulse conduction, or both. […] Bradyarrhythmias result from decreased intrinsic pacemaker function or blocks in conduction, principally within the AV node or the His-Purkinje system. […] Most tachyarrhythmias are caused by reentry; some result from enhanced normal automaticity or from abnormal mechanisms of automaticity. […] Reentry is the circular propagation of an impulse around 2 interconnected pathways with different conduction characteristics and refractory periods.

• #47 Analysis of the independent risk factors of second-degree atrioventric | IJGM

  https://www.dovepress.com/analysis-of-the-independent-risk-factors-of-second-degree-atrioventric-peer-reviewed-fulltext-article-IJGM

  Atrial fibrillation (AF) refers to arrhythmia caused by abnormal electrical activity in the upper chamber of the heart, which significantly reduces the efficiency of the heart in delivering blood to the ventricles, thereby increasing the risk of thrombosis and subsequent cerebral infarction. […] Atrioventricular block (AVB) refers to an abnormality in the conduction system of the heart at the atrioventricular node, which limits the pulsation of the lower ventricle of the heart. AVB is mainly caused by abnormal electrical conduction between the ventricles and atria, usually occurring during atrial fibrillation attacks. […] Second-degree AVB (II AVB) is one of the common complications in AF patients, with the electrocardiogram (ECG) commonly shows an R-R interval of 1.5 s and a high ventricular heart rate.

• #48 Analysis of the independent risk factors of second-degree atrioventric | IJGM

  https://www.dovepress.com/analysis-of-the-independent-risk-factors-of-second-degree-atrioventric-peer-reviewed-fulltext-article-IJGM

  However, in clinical practice, II AVB not only affects the patients heart function and reduces their quality of life, but may also leads to complications such as thromboembolism, tachycardia, and cardiomyopathy, endangering the patients life. […] The pathogenesis of AF is relatively complex, and increasing evidence suggests that the occurrence of AF is related to sudden cardiac death, cerebral infarction, and congestive heart failure. […] AVB is an abnormal conduction along the atrioventricular node or Hipper system, and different etiologies may lead to different outcomes. […] The results showed that smoking history, LAD, R-R interval, and ventricular rate were all influencing factors of AF combined with II AVB. […] The R-R interval exceeding 1.5 seconds and the appearance of escape rhythm are important features of atrial fibrillation.

• #49 AV Block: 2nd degree, Mobitz I (Wenckebach Phenomenon) • LITFL

  https://litfl.com/av-block-2nd-degree-mobitz-i-wenckebach-phenomenon/

  Mobitz I is usually due to reversible conduction block at the level of the AV node. […] Malfunctioning AV nodal cells tend to progressively fatigue until they fail to conduct an impulse. This is different to cells of the His-Purkinje system which tend to fail suddenly and unexpectedly (i.e. producing a Mobitz II block).

• #50 Mechanisms of cardiac arrhythmias: from automaticity to re-entry (reentry) – The Cardiovascular

  https://ecgwaves.com/topic/mechanisms-cardiac-arrhythmias-automaticity-reentry-triggered-activity/

  The sinoatrial node serves as the primary pacemaker of the heart simply because it possesses the fastest automaticity. […] The automaticity in the sinoatrial node increases during physical exercise. […] An action potential may induce an after-depolarization, which is a depolarization occurring either during or after the repolarization phase. […] Normal impulse transmission implies that the depolarizing wave spreads rapidly, uniformly and unhindered through the myocardium. […] It is fundamental to understand how re-entry occurs, as this mechanism is responsible for the majority of arrhythmias requiring treatment. […] Re-entry is the most common cause of supraventricular and ventricular arrhythmias that require treatment. Most cases of atrial flutter are due to re-entry and re-entry has a fundamental role in the development of atrial fibrillation. […] The re-entry circuit will terminate if the wavefront encounters refractory tissue (i.e. cells that cannot be depolarized).

• #51 Mechanisms of Cardiac Arrhythmias – Revista Española de Cardiología (English Edition)

  https://www.revespcardiol.org/en-mechanisms-of-cardiac-arrhythmias-articulo-S1885585711006086

  The EADs are oscillatory potentials that occur during the AP plateau (phase 2 EADs) or during the late repolarization (phase 3 EADs). […] Reentry has been divided in 2 main groups: anatomical or classic reentry, where the circuit is determined by anatomical structures, and functional reentry, which in turn includes different mechanisms. […] Prerequisites for reentry include: A substrate: the presence of joined myocardial tissue with different electrophysiological properties, conduction, and refractoriness. […] The classic reentry mechanism is based on an inexcitable anatomical obstacle surrounded by a circular pathway in which the wavefront can reenter, creating fixed and stable reentrant circuits. […] In functional reentry, the circuit is not determined by anatomic obstacles; it is defined by dynamic heterogeneities in the electrophysiologic properties of the involving tissue. […] The predominant mechanisms underlying most VTs are abnormal automaticity, TA, and reentry. The latter is the most frequent mechanism causing VT.

• #52 Mechanisms of Cardiac Arrhythmias – Revista Española de Cardiología (English Edition)

  https://www.revespcardiol.org/en-mechanisms-cardiac-arrhythmias-articulo-S1885585711006086

  Prerequisites for reentry include: A substrate: the presence of joined myocardial tissue with different electrophysiological properties, conduction, and refractoriness. […] The classic reentry mechanism is based on an inexcitable anatomical obstacle surrounded by a circular pathway in which the wavefront can reenter, creating fixed and stable reentrant circuits. […] Clinical examples: AV reentrant tachycardia associated with a bypass tract, AV nodal reentrant tachycardia, atrial flutter, bundle branch reentry VT, post-infarction VT. […] The predominant mechanisms underlying most VTs are abnormal automaticity, TA, and reentry. The latter is the most frequent mechanism causing VT.

• #53 Arrhythmias – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK558923/

  Mechanism: Accessory pathway present outside of the AV node-Bundle of Kent. […] Mechanism: Slow fast fibers present in AV node peri-nodal tissue leading to re-entry. […] Mechanism: Multiple reentrant wavelets due to atrial ectopy from muscle fibers near the proximal part of the pulmonary vein. […] Mechanism: Presence of damaged fibers in ischemic heart disease leading to re-entry of current leading to disorganized high-frequency excitation. […] Mechanism: It is usually precipitated by premature ventricular contraction leading to the R on T phenomenon. […] Bradyarrhythmia is defined as a heart rate below 60 beats per minute (bpm) and comprises several rhythm disorders, including atrioventricular (A-V) blocks and sinus node disorders. […] Mechanism: Atrial impulses are conducted with a delay or not at all when an electrical impulse reaches a tissue that not excitable or is in a refractory period. […] Mechanism: Senescence of the SA node, an ischemic event involving the SA node leading to impulse generation at a slower rate. […] Mechanism: Subaortic outflow tract obstruction from abnormal hypertrophy of the septal region of the heart, leading to precipitation of ventricular arrhythmias.

• #54 Cardiac arrhythmias pathophysiology | PPT

  https://www.slideshare.net/slideshow/cardiac-arrhythmias-pathophysiology/237187702

  Conversely, there may be enhanced automaticity of SA node leading to sinus tachycardia. […] Triggered activity (or after-depolarization) occur when a normal AP triggers extra-abnormal depolarisations. […] Two major forms of triggered rhythms are recognised: „delayed after-depolarization (DAD)” „early after-depolarisation (EAD)”. […] The third type of electrical disturbance of the heart involves defects in impulse conduction which can result from either one or combination of any of the three mechanisms: (a) conduction block, (b) re-entry phenomenon and (c) accessory tract pathways. […] It has been estimated that 80 to 90% of Clinical arrhythmias occur due to re entry phenomenon. […] In these patients an accessory atrioventricular pathway (a sort of bypass tract called bundle of Kent) is present.

• #55 Atrial Fibrillation

  https://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/cardiology/atrial-fibrillation/

  Atrial fibrillation (AF) is a common heart rhythm disorder caused by degeneration of the electrical impulses in the upper cardiac chambers (atria) resulting in a change from an organized heart rhythm to a rapid, chaotic rhythm. The resulting arrhythmia is often rapid and irregular with no discernible pattern (known as irregularly irregular). The disrupted rhythm occurs because of the unpredictable conduction of disordered impulses across the electrical bridge, called the atrioventricular (AV) node, to the lower cardiac chambers (ventricles). The arrhythmia also results in ineffectual atrial contractions affecting cardiac output and vulnerability to blood clot (thrombus) formation that can result in stroke events. […] Considerable research has been devoted to the mechanisms and pathogenesis of AF. Genetic studies have identified specific associations, particularly in the cases of familial AF. Achieving a complete understanding of AF is limited by the complexity of this disorder and the heterogeneous patient population it affects.

• #56 Heart Conduction System (Cardiac Conduction)

  https://my.clevelandclinic.org/health/body/21648-heart-conduction-system

  Several different conditions can affect your hearts electrical system. Cardiac conduction problems cause issues with your hearts rhythm. […] Some common heart rhythm disorders include: […] Arrhythmia. An irregular heart rhythm, including atrial fibrillation (Afib). […] Bundle branch block. A block in the Purkinje fibers on one side of your heart, causing arrhythmia. […] Heart block. Impaired electrical signals between your hearts atria and ventricles. […] Long QT syndrome (LQTS). Your ventricles contract and release too slowly, sometimes leading to fainting (syncope) or cardiac arrest. […] Premature ventricular contractions. A too-early heartbeat in your ventricles, causing heart palpitations or a skipped heartbeat. […] Cardiac arrest. A severe malfunction in your hearts rhythm that causes your heart to stop. Without immediate treatment, this is fatal.

• #57 Overview of Basic Mechanisms of Cardiac Arrhythmia

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3164530/

  In 2003, Burashnikov and Antzelevitch described a novel mechanism giving rise to triggered activity, termed late phase 3 EAD, which combines properties of both EAD and DAD, but has its own unique character. Late phase 3 EAD-induced triggered extrasystoles represent a new concept of arrhythmogenesis in which abbreviated repolarization permits normal SR calcium release to induce an EAD-mediated closely coupled triggered response, particularly under conditions permitting intracellular calcium loading. […] Reentry is fundamentally different from automaticity or triggered activity in the mechanism by which it initiates and sustains cardiac arrhythmias. Circus movement reentry occurs when an activation wavefront propagates around an anatomic or functional obstacle or core, and reexcites the site of origin. In this type of reentry, all cells take turns in recovering from excitation so that they are ready to be excited again when the next wavefront arrives. […] The mechanisms of arrhythmogenesis in BrS can be explained by the heterogeneous shortening of the APD on the right ventricular epicardium.

• #58 Overview of Basic Mechanisms of Cardiac Arrhythmia

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3164530/

  EADs are typically observed in cardiac tissues exposed to injury, altered electrolytes, hypoxia, acidosis, catecholamines, and pharmacologic agents, including antiarrhythmic drugs. Ventricular hypertrophy and heart failure also predispose to the development of EADs. EAD characteristics vary as a function of animal species, tissue or cell type, and the method by which the EAD is elicited. Although specific mechanisms of EAD induction can differ, a critical prolongation of repolarization accompanies most, but not all, EADs. Drugs that inhibit potassium currents or which augment inward currents predispose to the development of EADs. […] An example of DAD-induced arrhythmia is the catecholaminergic polymorphic ventricular tachycardia (CPVT), which may be caused by the mutation of either the type 2 ryanodine receptor (RyR2) or the calsequestrin (CSQ2). The principal mechanism underlying these arrhythmias is the leaky ryanodine receptor, which is aggravated during catecholamine stimulation. A typical clinical phenotype of CPVT is bidirectional ventricular tachycardia, which is also seen in digitalis toxicity.

• #59 New mechanism discovered for the life-threatening arrhythmias in Andersen-Tawil syndrome | EurekAlert!

  https://www.eurekalert.org/news-releases/1040441

  The study, published in Circulation Research, establishes a direct link between these life-threatening arrhythmias and the C122Y mutation in the Kir2.1 potassium channel. […] The study demonstrates that a specific genetic mutation (C122Y) in the Kir2.1 potassium channel alters the function not only of Kir2.1 but also of the main cardiac sodium channel NaV1.5, thus establishing a direct link with the life-threatening arrhythmias associated with ATS1. […] The study reveals that the C122Y mutation in Kir2.1 has a dual effect: it causes a reorganization of the Kir2.1 channel that destabilizes its binding to the phospholipid PIP2, a key lipid-signaling component of the cell membrane, and also disrupts the expression of the protein that forms the NaV1.5 channel, impairing its function. […] Dr. Jalife underscored the importance of the interaction between these channels for cardiac health, explaining that any alteration that disturbs the function of one or both channels can trigger life-threatening arrhythmias.

• #60 Overview of Basic Mechanisms of Cardiac Arrhythmia

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3164530/

  Bradycardia can occur in structurally normal hearts because of genetic mutations that result in abnormalities of either membrane clock or Ca clock mechanisms of automaticity. One example is the mutation of hyperpolarization-activated nucleotide-gated channel (HCN4), which is part of the channels that carry If. Mutations of the HCN4 may cause familial bradycardia as well. […] Common diseases, such as heart failure and atrial fibrillation, may be associated with significant SA node dysfunction. Malfunction of both membrane voltage and Ca clocks might be associated with both of these common diseases. Zicha and colleagues reported that down-regulation of HCN4 expression contributes to heart failure-induced sinus node dysfunction. An A450 V missense loss of function mutation in HCN4 has recently been shown to underlie familial sinus bradycardia in several unrelated probands of Moroccan Jewish descent.

• #61 Overview of Basic Mechanisms of Cardiac Arrhythmia

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3164530/

  Bradycardia can occur in structurally normal hearts because of genetic mutations that result in abnormalities of either membrane clock or Ca clock mechanisms of automaticity. One example is the mutation of hyperpolarization-activated nucleotide-gated channel (HCN4), which is part of the channels that carry If. Mutations of the HCN4 may cause familial bradycardia as well. […] Common diseases, such as heart failure and atrial fibrillation, may be associated with significant SA node dysfunction. Malfunction of both membrane voltage and Ca clocks might be associated with both of these common diseases. Zicha and colleagues reported that down-regulation of HCN4 expression contributes to heart failure-induced sinus node dysfunction. An A450 V missense loss of function mutation in HCN4 has recently been shown to underlie familial sinus bradycardia in several unrelated probands of Moroccan Jewish descent.

• #62 New mechanism discovered for the life-threatening arrhythmias in Andersen-Tawil syndrome | EurekAlert!

  https://www.eurekalert.org/news-releases/1040441

  The study, published in Circulation Research, establishes a direct link between these life-threatening arrhythmias and the C122Y mutation in the Kir2.1 potassium channel. […] The study demonstrates that a specific genetic mutation (C122Y) in the Kir2.1 potassium channel alters the function not only of Kir2.1 but also of the main cardiac sodium channel NaV1.5, thus establishing a direct link with the life-threatening arrhythmias associated with ATS1. […] The study reveals that the C122Y mutation in Kir2.1 has a dual effect: it causes a reorganization of the Kir2.1 channel that destabilizes its binding to the phospholipid PIP2, a key lipid-signaling component of the cell membrane, and also disrupts the expression of the protein that forms the NaV1.5 channel, impairing its function. […] Dr. Jalife underscored the importance of the interaction between these channels for cardiac health, explaining that any alteration that disturbs the function of one or both channels can trigger life-threatening arrhythmias.

• #63 New mechanism discovered for the life-threatening arrhythmias in Andersen-Tawil syndrome | EurekAlert!

  https://www.eurekalert.org/news-releases/1040441

  The discovery that a mutation considered 'monogenic’ disrupts not only the ion channel directly affected by the mutation, but also a complementary channel is important. […] The results of the new Circulation Research study support the hypothesis that the molecular mechanisms that increase susceptibility to arrhythmias and sudden cardiac death in ATS1 depend on the specific mutation, so that pharmacological treatment and clinical management should be tailored to each individual patient.

• #64 What Is Cardiac Arrhythmia? Types, Causes & Diagnosis – Avive AED

  https://www.avive.life/blog/arrhythmias-and-sudden-cardiac-arrest

  Sudden Cardiac Arrest (SCA) is an unexpected loss of heart function due to an underlying arrhythmia. During cardiac arrest, the heart is no longer able to pump oxygen to the brain or body. […] When someone suffers SCA, their heart is likely in either pulseless ventricular tachycardia or ventricular fibrillation. […] While many cardiac arrhythmias are not immediately dangerous, both of these lethal ventricular rhythms will lead to death within minutes if left untreated. […] Arrhythmias are caused by a diverse range of conditions and substances that affect the physiology and electrical function of the heart. The lethal arrhythmias that cause Sudden Cardiac Arrests are no different. […] Based on the type and severity of the arrhythmia, treatment can take many different forms. Some treatment options include:

• #65 Heart arrhythmia – Symptoms and causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/heart-arrhythmia/symptoms-causes/syc-20350668

  A heart arrhythmia (uh-RITH-me-uh) is an irregular heartbeat. A heart arrhythmia occurs when the electrical signals that tell the heart to beat don’t work properly. The heart may beat too fast or too slow. Or the pattern of the heartbeat may be inconsistent. […] A heart arrhythmia may feel like a fluttering, pounding or racing heartbeat. Some heart arrhythmias are harmless. Others may cause life-threatening symptoms. […] Heart arrhythmia treatment may include medicines, devices such as pacemakers, or a procedure or surgery. The goals of treatment are to control or get rid of fast, slow or otherwise irregular heartbeats. A heart-healthy lifestyle can help prevent heart damage that can trigger some heart arrhythmias. […] But some things can change how electrical signals travel through the heart and cause arrhythmias. They include: A heart attack or scarring from a previous heart attack. Blocked arteries in the heart, called coronary artery disease. Changes to the heart’s structure, such as from cardiomyopathy.

• #66 IJMS | Special Issue : Pathogenesis of Cardiac Arrhythmias and Heart Failure

  https://www.mdpi.com/journal/ijms/special_issues/cardiac_arrhythmias

  Cardiac arrhythmias are any of a group of conditions in which the electrical activity of the heart is irregular or is faster or slower than normal. Up to 50% of patients die suddenly at the first manifestation of cardiac diseases; the majority of these patients die of ventricular fibrillation, a lethal cardiac arrhythmia. Heart failure, a syndrome characterized by inadequate systemic perfusion owing to reduced cardiac pumping, is the most common cause of hospitalization of cardiovascular diseases and imposes a great burden on the healthcare system and society. […] Understanding the pathogenesis of cardiac arrhythmias and heart failure is critical to the development of diagnostic, treatment and preventive strategies. The current understanding of electrophysiological mechanisms of cardiac arrhythmias includes automaticity, triggered activity and reentry, and an understanding of pathogenetic mechanisms of heart failure includes a multitude of biomechanical, hemodynamic, hormonal and pathologic stimuli. However, the molecular pathways of cardiac arrhythmias and heart failure are still elusive, and novel molecular defects and pathways remain to be identified for screening, molecular diagnosis, drug-target development, and personalized medicine.

• #67 Heart arrhythmia – Symptoms and causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/heart-arrhythmia/symptoms-causes/syc-20350668

  A heart arrhythmia (uh-RITH-me-uh) is an irregular heartbeat. A heart arrhythmia occurs when the electrical signals that tell the heart to beat don’t work properly. The heart may beat too fast or too slow. Or the pattern of the heartbeat may be inconsistent. […] A heart arrhythmia may feel like a fluttering, pounding or racing heartbeat. Some heart arrhythmias are harmless. Others may cause life-threatening symptoms. […] Heart arrhythmia treatment may include medicines, devices such as pacemakers, or a procedure or surgery. The goals of treatment are to control or get rid of fast, slow or otherwise irregular heartbeats. A heart-healthy lifestyle can help prevent heart damage that can trigger some heart arrhythmias. […] But some things can change how electrical signals travel through the heart and cause arrhythmias. They include: A heart attack or scarring from a previous heart attack. Blocked arteries in the heart, called coronary artery disease. Changes to the heart’s structure, such as from cardiomyopathy.

• #68

  https://journals.lww.com/bjem/fulltext/2023/02030/a_review_of_arrhythmias_in_endocrinology.3.aspx

  Endocrine disorders can lead to cardiac arrhythmias, which can have serious implications for an individuals health, including sudden cardiac death. The pathophysiology of arrhythmias in endocrine disorders is a multifaceted process that includes alterations in hormone levels, disruptions in electrolyte levels, and changes to the hearts structure. Tachycardia and bradycardia are common rhythm abnormalities caused by defects in the cardiac conduction system or autonomic nervous system, metabolic disorders, and medication use. Therefore, it is crucial to identify and manage underlying endocrinopathies in patients with rhythm or conduction abnormalities. […] The onset of arrhythmias can be easily triggered in healthy hearts due to hormonal changes and electrolyte imbalances. Nonetheless, specific endocrine conditions can induce alterations in the hearts structure, which could potentially establish a long-lasting foundation for arrhythmias.

• #69

  https://journals.lww.com/bjem/fulltext/2023/02030/a_review_of_arrhythmias_in_endocrinology.3.aspx

  Identifying and managing underlying endocrinopathies is critical in patients who present with rhythm or conduction abnormalities, given the strong association between endocrine disorders and cardiac arrhythmias. Effective management of endocrine disorders can aid in preventing and treating cardiac arrhythmias. […] While diabetes can contribute to various types of cardiac arrhythmias, atrial fibrillation is the most commonly reported arrhythmia associated with diabetes. […] Diabetes has been associated with decreased heart rate variability, and both type 1 and type 2 diabetes have been shown to cause longer QT intervals. […] The likelihood of bradycardia, atrial ectopy, and ventricular arrhythmias is increased by hypoglycemia, especially at night, according to studies using continuous glucose monitoring and 24-h Holter monitoring.

• #70

  https://journals.lww.com/bjem/fulltext/2023/02030/a_review_of_arrhythmias_in_endocrinology.3.aspx

  Potassium imbalance is a major problem in diabetic ketoacidosis and can potentially lead to deadly arrhythmias. […] Certain anti-diabetic drugs may cause QT prolongation, either as a result of the drugs effect of hypoglycemia or as a direct side effect. […] Hypothyroidism can lead to a reduction in cardiac output of up to 30%40%, which can be attributed to a decrease in both stroke volume and heart rate. Additionally, hypothyroidism can cause varying degrees of conduction blocks. […] Most rhythm and conduction abnormalities identified in hypothyroidism can be quickly resolved with the start of levothyroxine medication in the proper dosage. […] In hypothyroidism, the expression of hepatic low-density lipoprotein receptors declines, which results in decreased cholesterol clearance and the development of hyperlipidemia.

• #71

  https://journals.lww.com/bjem/fulltext/2023/02030/a_review_of_arrhythmias_in_endocrinology.3.aspx

  The role of oral T3 supplementation and the risks of arrhythmias have not been extensively studied in the existing literature. […] Heart problems brought on by hyperthyroidism might include sinus tachycardia, elevated QRS complex voltage, and premature atrial and ventricular beats. […] Around 6%12% of patients with hyperthyroidism experience paroxysmal atrial tachycardia and atrial fibrillation. […] Patients who have structural or ischemic heart disease, long-standing atrial fibrillation, or who are older, are at a higher risk of developing persistent atrial fibrillation. […] The risk of stroke is reduced in those with chronic atrial fibrillation and hyperthyroidism compared to people without the condition, despite the fact that hyperthyroidism is associated with coagulation problems.

• #72 Arrhythmia: Symptoms & Treatment

  https://my.clevelandclinic.org/health/diseases/16749-arrhythmia

  If you have an arrhythmia, you should limit the amount of alcohol and caffeine you consume. Both of these can trigger arrhythmias. […] There are many ways for your heartbeat to be irregular. Some of these irregular heartbeats, called arrhythmias, dont cause symptoms. It’s important to see your healthcare provider if you do notice symptoms like extreme fatigue or heart palpitations.

• #73 Arrhythmia: Symptoms & Treatment

  https://my.clevelandclinic.org/health/diseases/16749-arrhythmia

  If you have an arrhythmia, you should limit the amount of alcohol and caffeine you consume. Both of these can trigger arrhythmias. […] There are many ways for your heartbeat to be irregular. Some of these irregular heartbeats, called arrhythmias, dont cause symptoms. It’s important to see your healthcare provider if you do notice symptoms like extreme fatigue or heart palpitations.

• #74 Analysis of the independent risk factors of second-degree atrioventric | IJGM

  https://www.dovepress.com/analysis-of-the-independent-risk-factors-of-second-degree-atrioventric-peer-reviewed-fulltext-article-IJGM

  However, in clinical practice, II AVB not only affects the patients heart function and reduces their quality of life, but may also leads to complications such as thromboembolism, tachycardia, and cardiomyopathy, endangering the patients life. […] The pathogenesis of AF is relatively complex, and increasing evidence suggests that the occurrence of AF is related to sudden cardiac death, cerebral infarction, and congestive heart failure. […] AVB is an abnormal conduction along the atrioventricular node or Hipper system, and different etiologies may lead to different outcomes. […] The results showed that smoking history, LAD, R-R interval, and ventricular rate were all influencing factors of AF combined with II AVB. […] The R-R interval exceeding 1.5 seconds and the appearance of escape rhythm are important features of atrial fibrillation.

• #75 Heart rhythm disorders – WikiLectures

  https://www.wikilectures.eu/w/Heart_rhythm_disorders

  Heart rhythm disorders (arytmie, dysrytmie) is a collective name for disorders of heart rate, heart rhythm, propagation of excitement in the heart or their combination. […] According to the pathogenetic mechanisms leading to individual arrhythmias, we distinguish: disorders of excitability; conduction disorders; combined disorders. […] The most common cause of arrhythmia is CHD (ischemia, hypoxia, acidosis, reperfusion injury). […] Ionic disorders (hypokalemia, hypomagnesia, hyperkalemia hypercalcemia); acid-base balance disorders; myocardial disorders: dilation or hypertrophy of the heart (cardiomyopathy, e.g. right ventricular cardiomyopathy is directly referred to as arrhythmogenic right ventricular dysplasia); inflammation (myocarditis); congenital and acquired heart defects. […] Disturbance of the balance of the vegetative nervous system (stress, anxiety shock, compensation of another pathological condition); arrhythmogenic substances (drugs, caffeine, adrenaline alcohol, digoxin, diuretics, antiarrhythmics); other diseases (endocrinopathy – thyrotoxicosis); cardiovascular autonomic neuropathy.

• #76 Pathological basis of cardiac arrhythmias: vicious cycle of immune-metabolic dysregulation

  https://www.oatext.com/pathological-basis-of-cardiac-arrhythmias-vicious-cycle-of-immune-metabolic-dysregulation.php

  Recently, the association of immunometabolic disorders with the occurrence of arrhythmias has emerged as a new horizon of studies; however, the underlying mechanism for immunometabolic disorder-associated arrhythmias remains poorly understood. In this paper, we review current evidence supporting the involvement of vicious cycle of immune-metabolic dysregulation in the pathogenesis of arrhythmias. […] In the pathogenesis of these CVDs, immunologic injury and metabolic disorders are essential factors that constitute the immunometabolic basis of cardiac arrhythmias. […] The immunopathogenesis of cardiac rhythm and conduction disorders have been identified in sick sinus syndrome, bradyarrhythmias, and hypersensitive carotid sinus syndrome. […] These facts support the proposal that autoimmunity and inflammation take part in electrical and structural remodeling of left atrium and predispose patients with autoimmune and inflammatory diseases to increased risk of arrhythmia.

• #77 Pathological basis of cardiac arrhythmias: vicious cycle of immune-metabolic dysregulation

  https://www.oatext.com/pathological-basis-of-cardiac-arrhythmias-vicious-cycle-of-immune-metabolic-dysregulation.php

  Recently, the association of immunometabolic disorders with the occurrence of arrhythmias has emerged as a new horizon of studies; however, the underlying mechanism for immunometabolic disorder-associated arrhythmias remains poorly understood. In this paper, we review current evidence supporting the involvement of vicious cycle of immune-metabolic dysregulation in the pathogenesis of arrhythmias. […] In the pathogenesis of these CVDs, immunologic injury and metabolic disorders are essential factors that constitute the immunometabolic basis of cardiac arrhythmias. […] The immunopathogenesis of cardiac rhythm and conduction disorders have been identified in sick sinus syndrome, bradyarrhythmias, and hypersensitive carotid sinus syndrome. […] These facts support the proposal that autoimmunity and inflammation take part in electrical and structural remodeling of left atrium and predispose patients with autoimmune and inflammatory diseases to increased risk of arrhythmia.

• #78 Inflammation and arrhythmogenesis: a narrative review of the complex relationship | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-024-00110-z

  Arrhythmias can be initiated or exacerbated by inflammation, which can change the electrophysiological properties of cardiac cells, such as ion channel expression, membrane potential, calcium handling, and gap junction coupling. […] Apoptosis, hypertrophy, and fibrosis are examples of structural changes that inflammation may cause in cardiac tissue. […] On the other hand, arrhythmias may cause or worsen inflammation by injuring the heart through mechanical strain, ischemiareperfusion, or oxidative stress. […] The aim of this narrative review is to clarify the intricate connection between inflammation and arrhythmogenesis, highlighting the numerous ways that both localized and systemic inflammation can affect the onset and course of different cardiac arrhythmias. […] There are several causes of systemic inflammation, including sepsis, trauma, surgery, and long-term illnesses.

• #79 Inflammation and arrhythmogenesis: a narrative review of the complex relationship | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-024-00110-z

  Arrhythmias can be initiated or exacerbated by inflammation, which can change the electrophysiological properties of cardiac cells, such as ion channel expression, membrane potential, calcium handling, and gap junction coupling. […] Apoptosis, hypertrophy, and fibrosis are examples of structural changes that inflammation may cause in cardiac tissue. […] On the other hand, arrhythmias may cause or worsen inflammation by injuring the heart through mechanical strain, ischemiareperfusion, or oxidative stress. […] The aim of this narrative review is to clarify the intricate connection between inflammation and arrhythmogenesis, highlighting the numerous ways that both localized and systemic inflammation can affect the onset and course of different cardiac arrhythmias. […] There are several causes of systemic inflammation, including sepsis, trauma, surgery, and long-term illnesses.

• #80 Inflammation and arrhythmogenesis: a narrative review of the complex relationship | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-024-00110-z

  Arrhythmias can be initiated or exacerbated by inflammation, which can change the electrophysiological properties of cardiac cells, such as ion channel expression, membrane potential, calcium handling, and gap junction coupling. […] Apoptosis, hypertrophy, and fibrosis are examples of structural changes that inflammation may cause in cardiac tissue. […] On the other hand, arrhythmias may cause or worsen inflammation by injuring the heart through mechanical strain, ischemiareperfusion, or oxidative stress. […] The aim of this narrative review is to clarify the intricate connection between inflammation and arrhythmogenesis, highlighting the numerous ways that both localized and systemic inflammation can affect the onset and course of different cardiac arrhythmias. […] There are several causes of systemic inflammation, including sepsis, trauma, surgery, and long-term illnesses.

• #81 Inflammation and arrhythmogenesis: a narrative review of the complex relationship | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-024-00110-z

  First, oxidative stress and cardiac cell damage from systemic inflammation might result in decreased electrical conduction and heightened vulnerability to reentry circuits. […] Second, the autonomic nervous system (ANS) might have its equilibrium upset by systemic inflammation. […] Third, since potassium, calcium, and magnesium are necessary for a proper ventricular action potential, systemic inflammation may have an impact on these electrolyte levels. […] Fourth, systemic inflammation has the potential to trigger the coagulation system and raise the risk of thromboembolism, both of which can result in myocardial infarction and ischemia. […] Systemic inflammatory markers were found to have high correlations with the development of atrial fibrillation/flutter (AF), ventricular arrhythmia (VA), and bradyarrhythmia in a research including 478,524 participants from the UK Biobank cohort.

• #82 Inflammation and arrhythmogenesis: a narrative review of the complex relationship | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-024-00110-z

  First, oxidative stress and cardiac cell damage from systemic inflammation might result in decreased electrical conduction and heightened vulnerability to reentry circuits. […] Second, the autonomic nervous system (ANS) might have its equilibrium upset by systemic inflammation. […] Third, since potassium, calcium, and magnesium are necessary for a proper ventricular action potential, systemic inflammation may have an impact on these electrolyte levels. […] Fourth, systemic inflammation has the potential to trigger the coagulation system and raise the risk of thromboembolism, both of which can result in myocardial infarction and ischemia. […] Systemic inflammatory markers were found to have high correlations with the development of atrial fibrillation/flutter (AF), ventricular arrhythmia (VA), and bradyarrhythmia in a research including 478,524 participants from the UK Biobank cohort.

• #83 Inflammation and arrhythmogenesis: a narrative review of the complex relationship | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-024-00110-z

  First, oxidative stress and cardiac cell damage from systemic inflammation might result in decreased electrical conduction and heightened vulnerability to reentry circuits. […] Second, the autonomic nervous system (ANS) might have its equilibrium upset by systemic inflammation. […] Third, since potassium, calcium, and magnesium are necessary for a proper ventricular action potential, systemic inflammation may have an impact on these electrolyte levels. […] Fourth, systemic inflammation has the potential to trigger the coagulation system and raise the risk of thromboembolism, both of which can result in myocardial infarction and ischemia. […] Systemic inflammatory markers were found to have high correlations with the development of atrial fibrillation/flutter (AF), ventricular arrhythmia (VA), and bradyarrhythmia in a research including 478,524 participants from the UK Biobank cohort.

• #84 Inflammation and arrhythmogenesis: a narrative review of the complex relationship | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-024-00110-z

  First, oxidative stress and cardiac cell damage from systemic inflammation might result in decreased electrical conduction and heightened vulnerability to reentry circuits. […] Second, the autonomic nervous system (ANS) might have its equilibrium upset by systemic inflammation. […] Third, since potassium, calcium, and magnesium are necessary for a proper ventricular action potential, systemic inflammation may have an impact on these electrolyte levels. […] Fourth, systemic inflammation has the potential to trigger the coagulation system and raise the risk of thromboembolism, both of which can result in myocardial infarction and ischemia. […] Systemic inflammatory markers were found to have high correlations with the development of atrial fibrillation/flutter (AF), ventricular arrhythmia (VA), and bradyarrhythmia in a research including 478,524 participants from the UK Biobank cohort.

• #85 Inflammation and arrhythmogenesis: a narrative review of the complex relationship | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-024-00110-z

  Specific infections include bacterial, fungal, or viral infections as well as autoimmune disorders can result in localized inflammation. […] First, there is a chance that localized inflammation will cause structural remodeling in cardiovascular tissue, in addition to processes like necrosis, apoptosis, and fibrosis. […] Second, localized inflammation may result in inflammation of the ganglia or cardiac nerves, which may change how the heart’s autonomic nervous system regulates itself. […] Third, localized inflammation may directly harm the heart’s cells, impairing their ability to handle calcium, boosting their automaticity, or making them more susceptible to catecholamines. […] Fourth, localized inflammation may compress or infiltrate the cardiac conduction system, including the His-Purkinje system, the atrioventricular node, and the sinoatrial node, which may result in heart block or bradyarrhythmias.

• #86 Inflammation and arrhythmogenesis: a narrative review of the complex relationship | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-024-00110-z

  Specific infections include bacterial, fungal, or viral infections as well as autoimmune disorders can result in localized inflammation. […] First, there is a chance that localized inflammation will cause structural remodeling in cardiovascular tissue, in addition to processes like necrosis, apoptosis, and fibrosis. […] Second, localized inflammation may result in inflammation of the ganglia or cardiac nerves, which may change how the heart’s autonomic nervous system regulates itself. […] Third, localized inflammation may directly harm the heart’s cells, impairing their ability to handle calcium, boosting their automaticity, or making them more susceptible to catecholamines. […] Fourth, localized inflammation may compress or infiltrate the cardiac conduction system, including the His-Purkinje system, the atrioventricular node, and the sinoatrial node, which may result in heart block or bradyarrhythmias.

• #87 Inflammation and arrhythmogenesis: a narrative review of the complex relationship | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-024-00110-z

  Specific infections include bacterial, fungal, or viral infections as well as autoimmune disorders can result in localized inflammation. […] First, there is a chance that localized inflammation will cause structural remodeling in cardiovascular tissue, in addition to processes like necrosis, apoptosis, and fibrosis. […] Second, localized inflammation may result in inflammation of the ganglia or cardiac nerves, which may change how the heart’s autonomic nervous system regulates itself. […] Third, localized inflammation may directly harm the heart’s cells, impairing their ability to handle calcium, boosting their automaticity, or making them more susceptible to catecholamines. […] Fourth, localized inflammation may compress or infiltrate the cardiac conduction system, including the His-Purkinje system, the atrioventricular node, and the sinoatrial node, which may result in heart block or bradyarrhythmias.

• #88 Inflammation and arrhythmogenesis: a narrative review of the complex relationship | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-024-00110-z

  Specific infections include bacterial, fungal, or viral infections as well as autoimmune disorders can result in localized inflammation. […] First, there is a chance that localized inflammation will cause structural remodeling in cardiovascular tissue, in addition to processes like necrosis, apoptosis, and fibrosis. […] Second, localized inflammation may result in inflammation of the ganglia or cardiac nerves, which may change how the heart’s autonomic nervous system regulates itself. […] Third, localized inflammation may directly harm the heart’s cells, impairing their ability to handle calcium, boosting their automaticity, or making them more susceptible to catecholamines. […] Fourth, localized inflammation may compress or infiltrate the cardiac conduction system, including the His-Purkinje system, the atrioventricular node, and the sinoatrial node, which may result in heart block or bradyarrhythmias.

• #89 Inflammation and arrhythmogenesis: a narrative review of the complex relationship | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-024-00110-z

  Specific infections include bacterial, fungal, or viral infections as well as autoimmune disorders can result in localized inflammation. […] First, there is a chance that localized inflammation will cause structural remodeling in cardiovascular tissue, in addition to processes like necrosis, apoptosis, and fibrosis. […] Second, localized inflammation may result in inflammation of the ganglia or cardiac nerves, which may change how the heart’s autonomic nervous system regulates itself. […] Third, localized inflammation may directly harm the heart’s cells, impairing their ability to handle calcium, boosting their automaticity, or making them more susceptible to catecholamines. […] Fourth, localized inflammation may compress or infiltrate the cardiac conduction system, including the His-Purkinje system, the atrioventricular node, and the sinoatrial node, which may result in heart block or bradyarrhythmias.

• #90 Inflammation and arrhythmogenesis: a narrative review of the complex relationship | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-024-00110-z

  Conditions like endocarditis, myocarditis, or pericarditis may result from localized inflammation that targets specific heart components. […] The following are the consequences of inflammation-induced arrhythmogenesis in the electrocardiogram (ECG): Inflammation can impact cardiomyocytes’ ion channel function, resulting in a delayed repolarization and a prolonged action potential duration (APD). […] Inflammation can also result in transmural and regional variations in the electrical characteristics of the heart tissue, including dispersion of repolarization, refractoriness, and conduction velocity. […] When there is inflammation, the heart’s tissue may be less able to adjust to variations in heart rate, which may occur during stress or exercise. […] Atrial fibrillation (AF), ventricular tachycardia (VT), and sudden cardiac death (SCD) are a few arrhythmias that can be prevented or treated by reducing inflammation.

• #91 Pathological basis of cardiac arrhythmias: vicious cycle of immune-metabolic dysregulation

  https://www.oatext.com/pathological-basis-of-cardiac-arrhythmias-vicious-cycle-of-immune-metabolic-dysregulation.php

  Cardiac arrhythmias are a major type of cardiovascular diseases and account for high morbidity and mortality. The occurrence of cardiac arrhythmias is closely associated with abnormal neurohumoral regulation of heart rhythmicity and the pathogenesis of many cardiovascular diseases, particularly coronary artery disease (CAD). Normal immunometabolic coupling between endoplasmic reticulum (ER) and mitochondria is an essential condition for normal heart rhythm. ER stress and mitochondrial oxidative stress evoked immunometabolic challenges can cause inflammation, lipotoxicity and cell apoptosis, leading to CAD and the ensuing arrhythmias. These disorders are associated with activation of inducible nitric oxide synthase, protein tyrosine nitration, malfunctioned chaperone, abnormal calcium signaling through mitochondria-associated ER membrane, disruption of oxidative phosphorylation, and activation of inflammatory and apoptotic pathways. In this review, we highlight the mechanisms underlying arrhythmias, specifically involving disorders in immuno-metabolic network and the underlying signaling process.

• #92 Pathological basis of cardiac arrhythmias: vicious cycle of immune-metabolic dysregulation

  https://www.oatext.com/pathological-basis-of-cardiac-arrhythmias-vicious-cycle-of-immune-metabolic-dysregulation.php

  The cellular type of immunological injury is associated with the activation of cytotoxic T-lymphocytes/cells. […] In the pathogenesis of CVDs and the resultant arrhythmias, immunologic injuries and metabolic disorders occur simultaneously and are intertwined to form a malfunctioned immunometabolic network. […] Together with a previous review, the facts presented above allow us to propose that accumulation of harmful lipids or generation of signaling intermediates can interfere with immune regulation in cardiac tissues and vice versa; they can form a vicious cycle of immune-metabolic dysregulation and in turn hurt cardiac functions. Thus, in studying on the pathogenesis of arrhythmias and therapeutic approaches, the immune states and metabolic conditions should be considered in an intact immunometabolic network.

• #93 Pathological basis of cardiac arrhythmias: vicious cycle of immune-metabolic dysregulation

  https://www.oatext.com/pathological-basis-of-cardiac-arrhythmias-vicious-cycle-of-immune-metabolic-dysregulation.php

  Immunometabolic disorders involve dysregulation of multiple organelles during cardiac injuries and the ensuing arrhythmia. ER stress and mitochondrial oxidative stress intersect immune injury and metabolic disorder, thereby highly representing malfunctions of immunometabolic network in arrhythmogenesis. […] It is important to note that ER stress can propagate through inactivation of inositol-requiring enzyme-1, the key ER regulator, through nitrosylation due to excessively produced NO following increased iNOS activity. […] We propose that ER is an important immunometabolic hub in the cardiac pathogenesis and the ensuing arrhythmias. […] ROS is a natural byproduct of the normal metabolism of oxygen including peroxides, superoxide, hydroxyl radical, and singlet oxygen. In diabetic cardiomyopathy and I/R, cardiac production of ROS can increase dramatically, resulting in oxidative stress and significant cellular damage.

• #94 Why heart rhythm problems tend to happen early in the morning | Imperial News | Imperial College London

  https://www.imperial.ac.uk/news/252500/why-heart-rhythm-problems-tend-happen/

  Researchers have uncovered why people are more likely to have heart arrhythmia first thing in the morning. […] Many studies have shown that potentially lethal heart rhythm disturbances (ventricular arrhythmia) are more likely to occur in the morning, when people wake after a nights sleep, but until now the trigger mechanism has not been fully understood. […] Now, research led by Imperial College London have revealed that these heart disturbances are linked to the natural surge of the stress hormone, cortisol, which peaks in our blood first thing in the morning. […] In a study in mice, they found that cortisol binds to a specific receptor in heart cells. The receptor moves to the nucleus where it influences the genes regulating ion channels in the cell membrane, which control heart beats. As the activity of the ion channels changes, the heart becomes much more vulnerable, since it is easier for the regular electrical impulses, which cause regular heart beats, to break down into more chaotic activity or arrhythmia.

• #95 Why heart rhythm disturbances are more likely early in the morning – BHF

  https://www.bhf.org.uk/what-we-do/news-from-the-bhf/news-archive/2024/april/why-heart-rhythm-disturbances-are-more-likely-to-happen-early-in-the-morning

  Research funded by us has revealed for the first time a mechanism explaining why potentially lethal heart rhythm disturbances are more likely to occur in the morning, when people wake after a nights sleep. […] These disturbances, known as ventricular arrhythmias, are linked to the natural surge of the stress hormone cortisol, which peaks in our blood first thing in the morning. […] As the activity of the genes change, electrical impulses to the heart become less regular and more chaotic, leading to abnormal heart rhythms, or arrhythmia. […] Ventricular arrhythmias can strike at any time and, if left untreated, can lead to a loss of consciousness, sudden cardiac arrest, and death. […] Identifying a rise in cortisol as the culprit could allow us to explore new treatment options that could reduce arrhythmias in those most at risk.

• #96 Why heart rhythm problems tend to happen early in the morning | Imperial News | Imperial College London

  https://www.imperial.ac.uk/news/252500/why-heart-rhythm-problems-tend-happen/

  Researchers have uncovered why people are more likely to have heart arrhythmia first thing in the morning. […] Many studies have shown that potentially lethal heart rhythm disturbances (ventricular arrhythmia) are more likely to occur in the morning, when people wake after a nights sleep, but until now the trigger mechanism has not been fully understood. […] Now, research led by Imperial College London have revealed that these heart disturbances are linked to the natural surge of the stress hormone, cortisol, which peaks in our blood first thing in the morning. […] In a study in mice, they found that cortisol binds to a specific receptor in heart cells. The receptor moves to the nucleus where it influences the genes regulating ion channels in the cell membrane, which control heart beats. As the activity of the ion channels changes, the heart becomes much more vulnerable, since it is easier for the regular electrical impulses, which cause regular heart beats, to break down into more chaotic activity or arrhythmia.

• #97 Why heart rhythm problems tend to happen early in the morning | Imperial News | Imperial College London

  https://www.imperial.ac.uk/news/252500/why-heart-rhythm-problems-tend-happen/

  The discovery of the link also raises the prospect of new treatments in this field. […] Lead researcher Alicia DSouza from Imperials National Heart and Lung Institute (HNLI) says: Our hearts are effectively different organs at different times of the day. They are more vulnerable first thing in the morning because of ancient circadian rhythms, which have evolved over millions of years. […] Ventricular arrhythmias can strike at any time and, if left untreated, can lead to a loss of consciousness, sudden cardiac arrest, and death. […] This intriguing study in mice reveals a possible solution to the mystery of why ventricular arrhythmias are more common in the morning. Identifying a rise in cortisol as the culprit could allow us to explore new treatment options that could reduce arrhythmias in those most at risk.

• #98 Why heart rhythm problems tend to happen early in the morning | Imperial News | Imperial College London

  https://www.imperial.ac.uk/news/252500/why-heart-rhythm-problems-tend-happen/

  The discovery of the link also raises the prospect of new treatments in this field. […] Lead researcher Alicia DSouza from Imperials National Heart and Lung Institute (HNLI) says: Our hearts are effectively different organs at different times of the day. They are more vulnerable first thing in the morning because of ancient circadian rhythms, which have evolved over millions of years. […] Ventricular arrhythmias can strike at any time and, if left untreated, can lead to a loss of consciousness, sudden cardiac arrest, and death. […] This intriguing study in mice reveals a possible solution to the mystery of why ventricular arrhythmias are more common in the morning. Identifying a rise in cortisol as the culprit could allow us to explore new treatment options that could reduce arrhythmias in those most at risk.

• #99 Why heart rhythm disturbances are more likely early in the morning – BHF

  https://www.bhf.org.uk/what-we-do/news-from-the-bhf/news-archive/2024/april/why-heart-rhythm-disturbances-are-more-likely-to-happen-early-in-the-morning

  The discovery of the link also raises the prospect of new treatments in this field. […] Our hearts are effectively different organs at different times of the day. They are more vulnerable first thing in the morning because of ancient circadian rhythms, which have evolved over millions of years. […] This study is the latest in a series in which Dr DSouza and Professor Mark Boyett from the University of Bradford have been exploring why the electrical activity of the heart shows an important day-night rhythm and why the heart is vulnerable to different arrhythmias at different times of the day or night.

• #100 Azthena logo with the word Azthena

  https://www.news-medical.net/news/20200218/Study-reveals-underlying-mechanism-for-life-threatening-cardiac-arrhythmias.aspx

  Low oxygen levels in the heart have long been known to produce life-threatening arrhythmias, even sudden death. Until now, it was not clear how. […] Our research shows that within seconds, at low levels of oxygen (hypoxia), a protein called small ubiquitin-like modifier (SUMO) is linked to the inside of the sodium channels which are responsible for starting each heartbeat. […] If sodium channels re-open and produce late sodium currents, as observed in this study with low oxygen levels, the action potential is prolonged and new electrical activity can begin before the heart has recovered risking dangerous, disorganized rhythms. […] This new research shows how rapid SUMOylation of cell surface cardiac sodium channels causes late sodium current in response to hypoxia, a challenge that confronts many people with heart disease. […] The information, gained through the current study, offers new targets for therapeutics to prevent late current and arrhythmia associated with heart attacks, chronic heart failure and other life-threatening low oxygen cardiac conditions.

• #101 Azthena logo with the word Azthena

  https://www.news-medical.net/news/20200218/Study-reveals-underlying-mechanism-for-life-threatening-cardiac-arrhythmias.aspx

  Low oxygen levels in the heart have long been known to produce life-threatening arrhythmias, even sudden death. Until now, it was not clear how. […] Our research shows that within seconds, at low levels of oxygen (hypoxia), a protein called small ubiquitin-like modifier (SUMO) is linked to the inside of the sodium channels which are responsible for starting each heartbeat. […] If sodium channels re-open and produce late sodium currents, as observed in this study with low oxygen levels, the action potential is prolonged and new electrical activity can begin before the heart has recovered risking dangerous, disorganized rhythms. […] This new research shows how rapid SUMOylation of cell surface cardiac sodium channels causes late sodium current in response to hypoxia, a challenge that confronts many people with heart disease. […] The information, gained through the current study, offers new targets for therapeutics to prevent late current and arrhythmia associated with heart attacks, chronic heart failure and other life-threatening low oxygen cardiac conditions.

• #102

  https://journals.lww.com/jtrauma/fulltext/9900/pad2_disturbs_cardiomyocyte_calcium_homeostasis_by.974.aspx

  In conclusion, we find that PAD2 plays a critical role in the pathogenesis of hemorrhagic shock-induced arrhythmias by regulating SERCA2a activity through citrullination. PAD2 inhibition may represent a novel therapeutic approach for mitigating cardiac dysfunction and improving survival rates in patients with traumatic hemorrhagic shock.

• #103 Arrhythmias: MedlinePlus Medical EncyclopediaLock

  https://medlineplus.gov/ency/article/001101.htm

  An arrhythmia is a disorder of the heart rate (pulse) or heart rhythm. The heart can beat too fast (tachycardia), too slow (bradycardia), or irregularly. […] Arrhythmias are caused by problems with the heart’s electrical conduction system. […] Abnormal extra signals may occur. […] Electrical signals may be blocked or slowed. […] Electrical signals travel in new or different pathways through the heart. […] Some common causes of abnormal heartbeats are: […] Arrhythmias may also be caused by some substances or drugs, including: […] Some of the more common abnormal heart rhythms are: […] When an arrhythmia is serious, you may need urgent treatment to restore a normal rhythm. […] Medicines called anti-arrhythmic drugs may be used: […] Other treatments to prevent or treat abnormal heart rhythms include: […] The outcome depends on several factors:

• #104 Palpitations – Cardiovascular Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/cardiovascular-disorders/symptoms-of-cardiovascular-disorders/palpitations

  Many arrhythmias that cause palpitations have no adverse physiologic consequences of their own (ie, independent of the underlying disorder). However, bradyarrhythmias, tachyarrhythmias, and heart blocks can be unpredictable and may adversely affect cardiac output and cause hypotension or death. Ventricular tachycardia sometimes degenerates to ventricular fibrillation. […] Most antiarrhythmic medications themselves can cause arrhythmias.

• #105 Overview of Basic Mechanisms of Cardiac Arrhythmia

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3164530/

  EADs are typically observed in cardiac tissues exposed to injury, altered electrolytes, hypoxia, acidosis, catecholamines, and pharmacologic agents, including antiarrhythmic drugs. Ventricular hypertrophy and heart failure also predispose to the development of EADs. EAD characteristics vary as a function of animal species, tissue or cell type, and the method by which the EAD is elicited. Although specific mechanisms of EAD induction can differ, a critical prolongation of repolarization accompanies most, but not all, EADs. Drugs that inhibit potassium currents or which augment inward currents predispose to the development of EADs. […] An example of DAD-induced arrhythmia is the catecholaminergic polymorphic ventricular tachycardia (CPVT), which may be caused by the mutation of either the type 2 ryanodine receptor (RyR2) or the calsequestrin (CSQ2). The principal mechanism underlying these arrhythmias is the leaky ryanodine receptor, which is aggravated during catecholamine stimulation. A typical clinical phenotype of CPVT is bidirectional ventricular tachycardia, which is also seen in digitalis toxicity.

• #106 Heart rhythm disorders – WikiLectures

  https://www.wikilectures.eu/w/Heart_rhythm_disorders

  Heart rhythm disorders (arytmie, dysrytmie) is a collective name for disorders of heart rate, heart rhythm, propagation of excitement in the heart or their combination. […] According to the pathogenetic mechanisms leading to individual arrhythmias, we distinguish: disorders of excitability; conduction disorders; combined disorders. […] The most common cause of arrhythmia is CHD (ischemia, hypoxia, acidosis, reperfusion injury). […] Ionic disorders (hypokalemia, hypomagnesia, hyperkalemia hypercalcemia); acid-base balance disorders; myocardial disorders: dilation or hypertrophy of the heart (cardiomyopathy, e.g. right ventricular cardiomyopathy is directly referred to as arrhythmogenic right ventricular dysplasia); inflammation (myocarditis); congenital and acquired heart defects. […] Disturbance of the balance of the vegetative nervous system (stress, anxiety shock, compensation of another pathological condition); arrhythmogenic substances (drugs, caffeine, adrenaline alcohol, digoxin, diuretics, antiarrhythmics); other diseases (endocrinopathy – thyrotoxicosis); cardiovascular autonomic neuropathy.

• #107

  https://journals.lww.com/bjem/fulltext/2023/02030/a_review_of_arrhythmias_in_endocrinology.3.aspx

  Potassium imbalance is a major problem in diabetic ketoacidosis and can potentially lead to deadly arrhythmias. […] Certain anti-diabetic drugs may cause QT prolongation, either as a result of the drugs effect of hypoglycemia or as a direct side effect. […] Hypothyroidism can lead to a reduction in cardiac output of up to 30%40%, which can be attributed to a decrease in both stroke volume and heart rate. Additionally, hypothyroidism can cause varying degrees of conduction blocks. […] Most rhythm and conduction abnormalities identified in hypothyroidism can be quickly resolved with the start of levothyroxine medication in the proper dosage. […] In hypothyroidism, the expression of hepatic low-density lipoprotein receptors declines, which results in decreased cholesterol clearance and the development of hyperlipidemia.

• #108 Society for Cardiovascular Angiography and Interventions

  https://www.healio.com/news/cardiology/20250506/cannabis-use-disorder-among-those-with-heart-failure-may-increase-mi-shock-arrhythmias

  Among patients with heart failure, those with cannabis use disorder had elevated odds for cardiogenic shock, MI and arrhythmias, researchers reported at the Society for Cardiovascular Angiography and Interventions Scientific Sessions. […] After adjustment for demographics, compared with nonusers, patients with cannabis use disorder had lower odds of mortality (adjusted OR = 0.51; 95% CI, 0.35-0.77; P.01) and respiratory failure (aOR = 0.75; 95% CI, 0.69-0.83; P.001) but higher odds of cardiogenic shock (aOR = 1.27; 95% CI, 1.08-1.49; P.01), MI (aOR = 1.5; 95% CI, 1.27-1.77; P.01) and arrhythmias (aOR = 1.48; 95% CI, 1.21-1.97; P.01), Ishaq and colleagues found. […] The negative cardiac effects are associated with the frequency of use, Ishaq told Healio. The more you are using it, the worse prognosis you are going to have in terms of MI, arrhythmias, cardiogenic shock, etc.

• #109 What supplements should you take for arrhythmia?

  https://www.medicalnewstoday.com/articles/supplements-for-arrhythmia-types-benefits-side-effects

  A doctor may recommend several dietary supplements, including magnesium, vitamin C, or coenzyme Q10 (Co Q10), to help a person with arrhythmia. […] When the heart does not beat with a typical rhythm and speed, health experts call this an arrhythmia. […] The most common is a fast pace with an irregular rhythm, which doctors call atrial fibrillation (AFib). […] Co Q10 supplementation may reduce mortality due to cardiovascular causes and decrease arterial stiffness and hypertension (high blood pressure). […] Some research suggests it has an antiarrhythmic effect, meaning it could correct a heartbeat that is too fast or irregular. However, further research is necessary to investigate this. […] Magnesium is an important mineral for regulating various bodily functions, including those that help establish a regular heart rhythm.

• #110 What supplements should you take for arrhythmia?

  https://www.medicalnewstoday.com/articles/supplements-for-arrhythmia-types-benefits-side-effects

  A 2020 retrospective study suggested magnesium, in combination with standard therapy, helped lower fast heart rates in people with AFib. […] Some research in a 2022 review suggests magnesium supplementation may help prevent AFib. However, the authors highlight the need for further research. […] According to a 2022 overview of systematic reviews, WXKL may be safe and effective in AFib treatment. However, more research is necessary to strengthen this conclusion. […] A 2021 study suggests ginger has various cardioprotective effects, including antihypertensive effects, which help lower blood pressure, antiplatelet effects, which help prevent heart attack and stroke, and antihyperlipidemia effects, which reduce the buildup of fats in the blood. […] A 2016 study suggests that 100 milligrams per kilogram of body weight of ginger as a daily oral supplement over 15 days significantly lowered the incidence of arrhythmia in rats.

• #111 What supplements should you take for arrhythmia?

  https://www.medicalnewstoday.com/articles/supplements-for-arrhythmia-types-benefits-side-effects

  A 2022 review suggests that vitamin C may be beneficial in treating AFib after heart surgery and may reduce recurrence after cardioversion. […] Supplements may help level out blood imbalances and restore heart rhythms to expected patterns. […] Electrical conduction problems, medications, stress or exertion, or blood imbalances can cause arrhythmias.

• #112 What supplements should you take for arrhythmia?

  https://www.medicalnewstoday.com/articles/supplements-for-arrhythmia-types-benefits-side-effects

  A 2020 retrospective study suggested magnesium, in combination with standard therapy, helped lower fast heart rates in people with AFib. […] Some research in a 2022 review suggests magnesium supplementation may help prevent AFib. However, the authors highlight the need for further research. […] According to a 2022 overview of systematic reviews, WXKL may be safe and effective in AFib treatment. However, more research is necessary to strengthen this conclusion. […] A 2021 study suggests ginger has various cardioprotective effects, including antihypertensive effects, which help lower blood pressure, antiplatelet effects, which help prevent heart attack and stroke, and antihyperlipidemia effects, which reduce the buildup of fats in the blood. […] A 2016 study suggests that 100 milligrams per kilogram of body weight of ginger as a daily oral supplement over 15 days significantly lowered the incidence of arrhythmia in rats.

• #113 What supplements should you take for arrhythmia?

  https://www.medicalnewstoday.com/articles/supplements-for-arrhythmia-types-benefits-side-effects

  A 2022 review suggests that vitamin C may be beneficial in treating AFib after heart surgery and may reduce recurrence after cardioversion. […] Supplements may help level out blood imbalances and restore heart rhythms to expected patterns. […] Electrical conduction problems, medications, stress or exertion, or blood imbalances can cause arrhythmias.

• #114 Atrial fibrillation | Nature Reviews Disease Primers

  https://www.nature.com/articles/s41572-022-00347-9

  Atrial fibrillation (AF) is the most common cardiac arrhythmia despite substantial efforts to understand the pathophysiology of the condition and develop improved treatments. […] Research has revealed that defects in specific molecular pathways underlie AF pathogenesis, resulting in electrical conduction disorders that drive AF. […] The severity of this so-called electropathology correlates with the stage of AF disease progression and determines the response to AF treatment. […] Therefore, unravelling the molecular mechanisms underlying electropathology is expected to fuel the development of innovative personalized diagnostic tools and mechanism-based therapies. […] Currently, various treatment modalities targeting AF-related electropathology, including lifestyle changes, pharmaceutical and nutraceutical therapy, substrate-based ablative therapy, and neuromodulation, are available to maintain sinus rhythm and might offer a novel holistic strategy to treat AF.

• #115 Propranolol: medicine for heart problems, anxiety and migraine – NHS

  https://www.nhs.uk/medicines/propranolol/

  Propranolol is used to treat conditions that cause an irregular heartbeat (arrhythmia), like atrial fibrillation. […] Propranolol can help reduce your symptoms if you have too much thyroid hormone in your body (thyrotoxicosis). […] Propranolol slows down your heart rate and makes it easier for your heart to pump blood around your body. […] Propranolol works by changing the way your body responds to some nerve impulses, including in the heart. It slows down your heart rate and makes it easier for your heart to pump blood around your body. […] Propranolol treats the physical symptoms of anxiety for example, it stops your heart beating too fast. […] You have shortness of breath with a cough which gets worse when you exercise (like walking up stairs), swollen ankles or legs, chest pain, or an irregular heartbeat these are signs of heart problems. […] Heart rhythm problems (arrhythmia)

• #116 Arrhythmia: Symptoms & Treatment

  https://my.clevelandclinic.org/health/diseases/16749-arrhythmia

  In addition to medicine, some people need therapies to treat or eliminate irregular heart rhythms. […] A cardiologist may insert certain devices during a procedure in the electrophysiology lab. Devices to treat a heart arrhythmia include permanent pacemakers and implantable cardioverter defibrillators (ICD). […] People with arrhythmias may require heart surgery for any of these reasons: to treat heart disease that may be causing the arrhythmia, including valve surgery or coronary artery bypass surgery. […] Depending on the type of cardiac arrhythmia you have, you may have mild or severe symptoms or none at all. You may not need treatment, but some people need medicine or a procedure. With heart arrhythmia treatment, many people can live full lives. […] Harmless arrhythmias go away and come back in response to what triggers them. However, people with other types of arrhythmias especially those that put you at risk for cardiac arrest need treatment for the rest of their lives.

• #117 New mechanism discovered for the life-threatening arrhythmias in Andersen-Tawil syndrome | EurekAlert!

  https://www.eurekalert.org/news-releases/1040441

  The discovery that a mutation considered 'monogenic’ disrupts not only the ion channel directly affected by the mutation, but also a complementary channel is important. […] The results of the new Circulation Research study support the hypothesis that the molecular mechanisms that increase susceptibility to arrhythmias and sudden cardiac death in ATS1 depend on the specific mutation, so that pharmacological treatment and clinical management should be tailored to each individual patient.

• #118 Why heart rhythm problems tend to happen early in the morning | Imperial News | Imperial College London

  https://www.imperial.ac.uk/news/252500/why-heart-rhythm-problems-tend-happen/

  The discovery of the link also raises the prospect of new treatments in this field. […] Lead researcher Alicia DSouza from Imperials National Heart and Lung Institute (HNLI) says: Our hearts are effectively different organs at different times of the day. They are more vulnerable first thing in the morning because of ancient circadian rhythms, which have evolved over millions of years. […] Ventricular arrhythmias can strike at any time and, if left untreated, can lead to a loss of consciousness, sudden cardiac arrest, and death. […] This intriguing study in mice reveals a possible solution to the mystery of why ventricular arrhythmias are more common in the morning. Identifying a rise in cortisol as the culprit could allow us to explore new treatment options that could reduce arrhythmias in those most at risk.

• #119 Why heart rhythm disturbances are more likely early in the morning – BHF

  https://www.bhf.org.uk/what-we-do/news-from-the-bhf/news-archive/2024/april/why-heart-rhythm-disturbances-are-more-likely-to-happen-early-in-the-morning

  The discovery of the link also raises the prospect of new treatments in this field. […] Our hearts are effectively different organs at different times of the day. They are more vulnerable first thing in the morning because of ancient circadian rhythms, which have evolved over millions of years. […] This study is the latest in a series in which Dr DSouza and Professor Mark Boyett from the University of Bradford have been exploring why the electrical activity of the heart shows an important day-night rhythm and why the heart is vulnerable to different arrhythmias at different times of the day or night.

• #120 Inflammation and arrhythmogenesis: a narrative review of the complex relationship | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-024-00110-z

  These consist of corticosteroids, NSAIDs, colchicine, statins, and biologics, among others. […] They may be used to treat inflammatory cardiomyopathies that increase the risk of arrhythmias, such as cardiac sarcoidosis, myocarditis, and rheumatic heart disease. […] By modifying the electrophysiological characteristics of cardiac cells, such as ion channel function, calcium handling, and gap junction coupling, they may also have anti-arrhythmic effects. […] The kind, etiology, and severity of the arrhythmias, as well as the patient’s features and comorbidities, may all affect how effective certain treatment techniques are.

• #121 Azthena logo with the word Azthena

  https://www.news-medical.net/news/20200218/Study-reveals-underlying-mechanism-for-life-threatening-cardiac-arrhythmias.aspx

  Low oxygen levels in the heart have long been known to produce life-threatening arrhythmias, even sudden death. Until now, it was not clear how. […] Our research shows that within seconds, at low levels of oxygen (hypoxia), a protein called small ubiquitin-like modifier (SUMO) is linked to the inside of the sodium channels which are responsible for starting each heartbeat. […] If sodium channels re-open and produce late sodium currents, as observed in this study with low oxygen levels, the action potential is prolonged and new electrical activity can begin before the heart has recovered risking dangerous, disorganized rhythms. […] This new research shows how rapid SUMOylation of cell surface cardiac sodium channels causes late sodium current in response to hypoxia, a challenge that confronts many people with heart disease. […] The information, gained through the current study, offers new targets for therapeutics to prevent late current and arrhythmia associated with heart attacks, chronic heart failure and other life-threatening low oxygen cardiac conditions.

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