Materiały źródłowe

• #1 Wolff-Parkinson-White Syndrome – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK554437/

  Wolff-Parkinson-White (WPW) syndrome is a congenital cardiac preexcitation syndrome that arises from abnormal cardiac electrical conduction through an accessory pathway that can result in symptomatic and life-threatening arrhythmias. […] Patients with WPW syndrome have an accessory pathway that violates the electrical isolation of the atria and ventricles, which can allow electrical impulses to bypass the AV node. In some settings, this pathway can result in the transmission of abnormal electrical impulses leading to malignant tachyarrhythmias. […] WPW pattern arises from the fusion of ventricular preexcitation through the accessory pathway and normal electrical conduction through the AV node. This accessory pathway is thought to arise from chamber myocardium during improper early atrial and ventricular folding in cardiac embryogenesis. As a result, electrically conductive myocardial bundles violate the normal electrical insulation of the atrium and ventricle, forming the accessory pathway.

• #2 Wolff-Parkinson-White Syndrome: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/159222-overview

  Accessory pathways or connections between the atrium and ventricle are the result of anomalous embryonic development of myocardial tissue bridging the fibrous tissues that separate the two chambers. This allows electrical conduction between the atria and ventricles at sites other than the AV node. Passage through APs circumvents the usual conduction delay between the atria and ventricles, which normally occurs at the AV node, and predisposes the patient to develop tachydysrhythmias. […] The primary feature that differentiates WPW syndrome from other AP-mediated supraventricular tachycardias (SVTs) is the ability of the AP to conduct in either an antegrade (ie, from atrium to ventricles) or a retrograde manner. […] The presence of an AP sets up the potential for reentrant tachycardia circuits to be established or for preexcited tachycardia in the setting of atrial fibrillation, atrial flutter, or SVT with a bystander accessory pathway. This reentrant mechanism is the typical cause of the SVT of which patients with preexcitation are at risk. The genesis of reentrant SVT involves the presence of dual conducting pathways between the atria and the ventricles.

• #3 Wolff–Parkinson–White syndrome – Wikipedia

  https://en.wikipedia.org/wiki/Wolff%E2%80%93Parkinson%E2%80%93White_syndrome

  WolffParkinsonWhite syndrome (WPWS) is a disorder due to a specific type of problem with the electrical system of the heart involving an accessory pathway able to conduct electrical current between the atria and the ventricles, thus bypassing the atrioventricular node. […] The underlying mechanism involves an accessory electrical conduction pathway between the atria and the ventricles. […] Individuals with WPW have an accessory pathway that communicates between the atria and the ventricles, in addition to the AV node. […] This accessory pathway is known as the bundle of Kent. […] Problems arise when this pathway creates an electrical circuit that bypasses the AV node. […] When an aberrant electrical connection is made via the bundle of Kent, tachydysrhythmias may therefore result.

• #4 Patient education: Wolff-Parkinson-White syndrome (Beyond the Basics) – UpToDate

  https://www.uptodate.com/contents/wolff-parkinson-white-syndrome-beyond-the-basics

  Wolff-Parkinson-White (WPW) syndrome is a condition in which episodes of fast heart rate (called tachycardia) occur because of an abnormal extra electrical pathway in the heart. […] People with WPW syndrome have an extra electrical pathway between the atria and the ventricles, known as an „accessory pathway.” This abnormal pathway directly connects the atria and ventricles at a site other than the AV node. […] An accessory pathway allows the electrical signal to travel from the atria to the ventricles more quickly than normal, bypassing the AV node where the electrical signal travels more slowly. […] The presence of two pathways (the normal one and the accessory one) between the atria and ventricles poses a risk of developing a „short circuit” of the normal electrical pathway, which can result in an abnormally fast heart rate (tachycardia).

• #5 Wolff-Parkinson-White Syndrome: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/159222-overview

  Accessory pathways or connections between the atrium and ventricle are the result of anomalous embryonic development of myocardial tissue bridging the fibrous tissues that separate the two chambers. This allows electrical conduction between the atria and ventricles at sites other than the AV node. Passage through APs circumvents the usual conduction delay between the atria and ventricles, which normally occurs at the AV node, and predisposes the patient to develop tachydysrhythmias. […] The primary feature that differentiates WPW syndrome from other AP-mediated supraventricular tachycardias (SVTs) is the ability of the AP to conduct in either an antegrade (ie, from atrium to ventricles) or a retrograde manner. […] The presence of an AP sets up the potential for reentrant tachycardia circuits to be established or for preexcited tachycardia in the setting of atrial fibrillation, atrial flutter, or SVT with a bystander accessory pathway. This reentrant mechanism is the typical cause of the SVT of which patients with preexcitation are at risk. The genesis of reentrant SVT involves the presence of dual conducting pathways between the atria and the ventricles.

• #6 Genetic basis and pathogenesis of Familial WPW Syndrome

  https://pmc.ncbi.nlm.nih.gov/articles/PMC1502052/

  The increased thickness of the myocardium (cardiac hypertrophy) has been attributed to the excessive deposition of glycogen-like substance as well as increased myocyte growth, which maybe somewhat different from the hypertrophy seen in HCM (hypertrophic cardiomyopathy) which is secondary only to increased myocyte growth and fibrosis. […] Conduction abnormalities (heart block or slowing of the conduction system) can be explained by two well established facts. First glycogen is known to be more abundant in the conduction system compared to the myocardial muscle tissue. Therefore excess accumulation of glycogen-like substance could lead to loss of conduction tissue and slowing or block. […] WPW syndrome in humans is caused by the existence of an accessory pathway. Initially there is no separation between the atria and the ventricles. During development either through apoptosis or remodeling the atria separates from the ventricle. It is possible that the normal developmental process of apoptosis and remodeling doesn’t occur in patients with familial WPW syndrome.

• #7 Wolf–Parkinson–White Syndrome: Diagnosis, Risk Assessment, and Therapy—An Update

  https://www.mdpi.com/2075-4418/14/3/296

  Wolf–Parkinson–White (WPW) syndrome is a disorder characterized by the presence of at least one accessory pathway (AP) that can predispose people to atrial/ventricular tachyarrhythmias and even sudden cardiac death. […] In the 1970s–1980s, Wolff–Parkinson–White (WPW) syndrome was the main subject of several studies involving its epidemiology and pathogenesis. […] Up to this point, only a limited number of genes have been identified as potential causes of WPW syndrome; further research in this area is needed. The genetic foundation of the syndrome remains poorly understood, particularly considering its incomplete penetrance and undetermined inheritance patterns in the majority of individuals. […] APs are aberrant muscle bundles that connect the atrium to the ventricle outside the regular atrioventricular conduction system. They are embryologic remnants due to incomplete embryological development of the atrioventricular (AV) annuli without complete separation of the atria and ventricles.

• #8 Wolff-Parkinson-White Syndrome | Treatment & Management | Point of Care

  https://www.statpearls.com/point-of-care/31383

  WPW pattern arises from the fusion of ventricular preexcitation through the accessory pathway and normal electrical conduction through the AV node. […] This accessory pathway is thought to arise from chamber myocardium during improper early atrial and ventricular folding in cardiac embryogenesis. […] As a result, electrically conductive myocardial bundles violate the normal electrical insulation of the atrium and ventricle, forming the accessory pathway. […] WPW ECG pattern is caused by abnormal electrical conduction through an accessory pathway that bypasses the normal cardiac conduction system. […] This accessory pathway allows cardiac electrical activity to bypass the atrioventricular node conduction delay, and arrive early at the ventricle, leading to premature ventricular depolarization.

• #9 Wolf–Parkinson–White Syndrome: Diagnosis, Risk Assessment, and Therapy—An Update

  https://www.mdpi.com/2075-4418/14/3/296

  Various other protein and receptor dysfunctions have been associated with not only the discontinuity of the annulus but also with the gap being bypassed by fast-conducting tissue. […] Most of the pathways identified through the use of microscopy have been working myocardium, with only a few reported to contain histologically specialized cells. […] Conduction through the bypass tracts can be anterograde, retrograde, or both. […] The diagnosis of WPW syndrome is reserved strictly for patients who have both pre-excitation and symptoms. […] The main electrocardiographic features of pre-excitation are short PR interval (<0.12 s), prolonged QRS complex (>0.12 s), and slurred, slow-rising onset of the QRS complex, known as delta wave. […] The clinical presentation of WPW syndrome is generally unspecific, extremely variable, and, most importantly, it usually accompanies arrhythmic episodes.

• #10 Genetic basis and pathogenesis of Familial WPW Syndrome

  https://pmc.ncbi.nlm.nih.gov/articles/PMC1502052/

  The Wolff-Parkinson-White (WPW) syndrome has been a known clinical entity for over fifty years. In 1967 Durrer et al postulated WPW syndrome was due to an accessory pathway, bypassing the AV node, from the atria to the ventricles. This was later confirmed by epicardial mapping. […] We recently identified the gene responsible for familial Wolff-Parkinson-White. The gene (PRKAG2) which encodes for a protein AMPK (AMP- activated protein kinase) was identified as the causal gene. Missense (single nucleotide change) mutations in this gene were identified in families with WPW. […] Families with WPW syndrome exhibit a variable phenotype consisting of cardiac hypertrophy, preexcitation, and conduction abnormalities. The syndrome is caused by missense mutations (single nucleotide change) in the gene PKRAG2 which encodes for the gamma-2 subunit of AMPK.

• #11

  https://omim.org/entry/194200

  A number sign (#) is used with this entry because of evidence that Wolff-Parkinson-White syndrome (WPW) is caused by heterozygous mutation in the gamma-2 regulatory subunit of AMP-activated protein kinase (PRKAG2; 602743) on chromosome 7q36. […] Mutation in the PRKAG2 gene can also cause a form of hypertrophic cardiomyopathy in which some patients exhibit WPW (CMH6; 600858). […] Gollob et al. (2001) noted that the PRKAG2 gene is located in the critical genomic region of the WPW syndrome locus identified by linkage on chromosome 7q34-q36. In affected members of 2 families with WPW syndrome, they identified an arg302-to-gln mutation (R302N; 602743.0001) in the PRKAG2 gene. An additional sequence variation at nucleotide 1912 in the 3-prime untranslated region of PRKAG2 was present in all affected members of family 2 but not family 1, indicating that the 2 families were unrelated.

• #12 Wolff-Parkinson-White syndrome pathophysiology – wikidoc

  https://www.wikidoc.org/index.php/Wolff-Parkinson-White_syndrome_pathophysiology

  The conduction through the accessory pathway can be bidirectional (most commonly): retrogarde (also known as concealed) as well as antegrade (also known as manifest, responsible for the ECG findings of delta wave and short PR interval). […] The most common type of tachycardia associated with WPW is atrioventricular reciprocating tachycardia (AVRT). […] The accessory pathway does not share the rate-slowing properties of the AV node, and may conduct electrical activity at a significantly higher rate than the AV node. […] The combination of an accessory pathway and tachyarrhythmia can trigger ventricular fibrillation and sudden cardiac death. […] The missense Mutation in PKRAG2 has been associated with the development of familiar WPW syndrome and cardiac hypertrophy, involving the gamma-2 subunit of AMPK pathway.

• #13 Genetic basis and pathogenesis of Familial WPW Syndrome

  https://pmc.ncbi.nlm.nih.gov/articles/PMC1502052/

  The Wolff-Parkinson-White (WPW) syndrome has been a known clinical entity for over fifty years. In 1967 Durrer et al postulated WPW syndrome was due to an accessory pathway, bypassing the AV node, from the atria to the ventricles. This was later confirmed by epicardial mapping. […] We recently identified the gene responsible for familial Wolff-Parkinson-White. The gene (PRKAG2) which encodes for a protein AMPK (AMP- activated protein kinase) was identified as the causal gene. Missense (single nucleotide change) mutations in this gene were identified in families with WPW. […] Families with WPW syndrome exhibit a variable phenotype consisting of cardiac hypertrophy, preexcitation, and conduction abnormalities. The syndrome is caused by missense mutations (single nucleotide change) in the gene PKRAG2 which encodes for the gamma-2 subunit of AMPK.

• #14 Genetic basis and pathogenesis of Familial WPW Syndrome

  https://pmc.ncbi.nlm.nih.gov/articles/PMC1502052/

  The increased thickness of the myocardium (cardiac hypertrophy) has been attributed to the excessive deposition of glycogen-like substance as well as increased myocyte growth, which maybe somewhat different from the hypertrophy seen in HCM (hypertrophic cardiomyopathy) which is secondary only to increased myocyte growth and fibrosis. […] Conduction abnormalities (heart block or slowing of the conduction system) can be explained by two well established facts. First glycogen is known to be more abundant in the conduction system compared to the myocardial muscle tissue. Therefore excess accumulation of glycogen-like substance could lead to loss of conduction tissue and slowing or block. […] WPW syndrome in humans is caused by the existence of an accessory pathway. Initially there is no separation between the atria and the ventricles. During development either through apoptosis or remodeling the atria separates from the ventricle. It is possible that the normal developmental process of apoptosis and remodeling doesn’t occur in patients with familial WPW syndrome.

• #15 Wolff-Parkinson-White syndrome: MedlinePlus GeneticsLock

  https://medlineplus.gov/genetics/condition/wolff-parkinson-white-syndrome/

  Researchers are uncertain how PRKAG2 gene variants lead to the development of Wolff-Parkinson-White syndrome and related heart abnormalities. […] Studies indicate that changes in AMP-activated protein kinase activity allow a complex sugar called glycogen to build up abnormally within cardiac muscle cells. Other studies have found that altered AMP-activated protein kinase activity is related to changes in the regulation of certain ion channels in the heart. These channels, which transport positively charged atoms (ions) into and out of cardiac muscle cells, play critical roles in maintaining the heart’s normal rhythm.

• #16 Pre-excitation syndromes • LITFL • ECG Library Diagnosis

  https://litfl.com/pre-excitation-syndromes-ecg-library/

  WPW Syndrome refers to the presence of a congenital accessory pathway (AP) and episodes of tachyarrhythmias. The term is often used interchangeablely with pre-excitation syndrome […] Pre-excitation refers to early activation of the ventricles due to impulses bypassing the AV node via an AP. Also known as bypass tracts, APs are abnormal conduction pathways formed during cardiac development and can exist in a variety of anatomical locations and in some patients there may be multiple pathways. In WPW, the AP is sometimes referred to as the Bundle of Kent, or atrioventricular bypass tract. […] An AP can conduct impulses in three ways: In both directions (majority), Retrograde only, away from the ventricle (15%), Anterograde only, towards the ventricle (rare). […] The direction of conduction affects the appearance of the ECG in sinus rhythm and during tachyarrhythmias.

• #17 Wolff-Parkinson-White Syndrome (WPW Syndrome) – Cardiovascular Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/cardiovascular-disorders/specific-cardiac-arrhythmias/wolff-parkinson-white-syndrome-wpw-syndrome

  Classic (manifest) Wolff-Parkinson-White syndrome is due to an accessory atrioventricular connection that produces a prototypical ECG consisting of a short PR interval, a wide QRS complex with an initial slurred component (delta wave), and secondary repolarization changes in association with symptomatic reentrant (paroxysmal) supraventricular tachycardia. […] An accessory pathway connecting an atrium and a ventricle is the substrate for the Wolff-Parkinson-White syndrome. When the accessory AV connection conducts in the antegrade direction, the AV nodal delay is bypassed and a portion of ventricular myocardium is activated before the rest is activated by the normal conduction system. This ventricular pre-excitation produces a short PR interval. […] The accessory atrioventricular connection in WPW syndrome behaves like atrial myocardium, a fast channel tissue, the refractory period of which shortens with increasing rates. Accordingly, should a rapid supraventricular rhythm occur, the ventricular response may not be controlled by the usual increased refractoriness of the AV node as the accessory AV connection may be able to conduct at very rapid rates. This is particularly relevant to the ventricular response rate to atrial fibrillation which may be sufficiently rapid as to produce hemodynamic compromise and may induce ventricular fibrillation and sudden death. […] WPW syndrome is mainly idiopathic, although it is more common among patients with hypertrophic cardiomyopathy, transposition of the great vessels, or Epstein’s anomaly.

• #18 Wolff-Parkinson-White syndrome pathophysiology – wikidoc

  https://www.wikidoc.org/index.php/Wolff-Parkinson-White_syndrome_pathophysiology

  In normal individuals, electrical activity in the heart is initiated in the sinoatrial (SA) node (located in the right atrium), propagates to the atrioventricular (AV) node, and then through the bundle of His to the ventricles of the heart. Individuals with Wolf-parkinson-White (WPW) have an accessory pathway, known as the bundle of Kent, that communicates between the atria and the ventricles. The conduction through the accessory pathway can be bidirectional (most commonly), only retrogarde (less common), or only antegrade (least common). The most common type of tachycardia associated with WPW is atrioventricular reciprocating tachycardia (AVRT). The accessory pathway does not share the rate-slowing properties of the AV node; therefore, the combination of an accessory pathway and cardiac arrhythmia can trigger ventricular fibrillation, a leading cause of sudden cardiac death.

• #19 Wolff–Parkinson–White syndrome – Wikipedia

  https://en.wikipedia.org/wiki/Wolff%E2%80%93Parkinson%E2%80%93White_syndrome

  WPW may be associated with PRKAG2, a protein kinase enzyme encoded by the PRKAG2 gene. […] The bundle of Kent is an abnormal extra or accessory conduction pathway between the atria and ventricles that is present in a small percentage (between 0.1 and 0.3%) of the general population. […] This pathway may communicate between the left atrium and the left ventricle, in which case it is termed a „type A pre-excitation”, or between the right atrium and the right ventricle, in which case it is termed a „type B pre-excitation” in old, currently abandoned classification. […] The AV node is capable of slowing the rate of conduction of electrical impulses to the ventricles, whereas the bundle of Kent lacks this capability.

• #20 Wolff-Parkinson-White syndrome pathophysiology – wikidoc

  https://www.wikidoc.org/index.php/Wolff-Parkinson-White_syndrome_pathophysiology

  The conduction through the accessory pathway can be bidirectional (most commonly): retrogarde (also known as concealed) as well as antegrade (also known as manifest, responsible for the ECG findings of delta wave and short PR interval). […] The most common type of tachycardia associated with WPW is atrioventricular reciprocating tachycardia (AVRT). […] The accessory pathway does not share the rate-slowing properties of the AV node, and may conduct electrical activity at a significantly higher rate than the AV node. […] The combination of an accessory pathway and tachyarrhythmia can trigger ventricular fibrillation and sudden cardiac death. […] The missense Mutation in PKRAG2 has been associated with the development of familiar WPW syndrome and cardiac hypertrophy, involving the gamma-2 subunit of AMPK pathway.

• #21 Wolff-Parkinson-White Syndrome (WPW Syndrome) – Cardiovascular Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/cardiovascular-disorders/specific-cardiac-arrhythmias/wolff-parkinson-white-syndrome-wpw-syndrome

  Classic (manifest) Wolff-Parkinson-White syndrome is due to an accessory atrioventricular connection that produces a prototypical ECG consisting of a short PR interval, a wide QRS complex with an initial slurred component (delta wave), and secondary repolarization changes in association with symptomatic reentrant (paroxysmal) supraventricular tachycardia. […] An accessory pathway connecting an atrium and a ventricle is the substrate for the Wolff-Parkinson-White syndrome. When the accessory AV connection conducts in the antegrade direction, the AV nodal delay is bypassed and a portion of ventricular myocardium is activated before the rest is activated by the normal conduction system. This ventricular pre-excitation produces a short PR interval. […] The accessory atrioventricular connection in WPW syndrome behaves like atrial myocardium, a fast channel tissue, the refractory period of which shortens with increasing rates. Accordingly, should a rapid supraventricular rhythm occur, the ventricular response may not be controlled by the usual increased refractoriness of the AV node as the accessory AV connection may be able to conduct at very rapid rates. This is particularly relevant to the ventricular response rate to atrial fibrillation which may be sufficiently rapid as to produce hemodynamic compromise and may induce ventricular fibrillation and sudden death. […] WPW syndrome is mainly idiopathic, although it is more common among patients with hypertrophic cardiomyopathy, transposition of the great vessels, or Epstein’s anomaly.

• #22 Wolff-Parkinson-White Syndrome – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK554437/

  WPW ECG pattern is caused by abnormal electrical conduction through an accessory pathway that bypasses the normal cardiac conduction system. This accessory pathway allows cardiac electrical activity to bypass the atrioventricular node conduction delay, and arrive early at the ventricle, leading to premature ventricular depolarization. […] There are two ways in which an accessory pathway can lead to WPW syndrome. The pathway can either initiate and maintain an arrhythmia or allow conduction of an arrhythmia generated elsewhere. […] The other way an accessory pathway can lead to arrhythmia is by allowing conduction of an arrhythmia that is generated elsewhere to propagate to a portion of the heart that would normally be electrically insulated from this arrhythmia. […] The feared complication of WPW syndrome is sudden cardiac death (SCD). Population studies suggest that SCD is most often a result of ventricular fibrillation leading to cardiac arrest or with atrial fibrillation or circus movement tachycardia. The mechanism for deterioration to ventricular fibrillation leading to SCD is an accessory pathway that is capable of rapid antegrade conduction that allows rapid transmission of atrial impulses to the ventricle.

• #23 Wolf–Parkinson–White Syndrome: Diagnosis, Risk Assessment, and Therapy—An Update

  https://www.mdpi.com/2075-4418/14/3/296

  Various other protein and receptor dysfunctions have been associated with not only the discontinuity of the annulus but also with the gap being bypassed by fast-conducting tissue. […] Most of the pathways identified through the use of microscopy have been working myocardium, with only a few reported to contain histologically specialized cells. […] Conduction through the bypass tracts can be anterograde, retrograde, or both. […] The diagnosis of WPW syndrome is reserved strictly for patients who have both pre-excitation and symptoms. […] The main electrocardiographic features of pre-excitation are short PR interval (<0.12 s), prolonged QRS complex (>0.12 s), and slurred, slow-rising onset of the QRS complex, known as delta wave. […] The clinical presentation of WPW syndrome is generally unspecific, extremely variable, and, most importantly, it usually accompanies arrhythmic episodes.

• #24 Wolff-Parkinson-White Syndrome: What Treatment?

  https://www.patientcareonline.com/view/wolff-parkinson-white-syndrome-what-treatment

  WPW syndrome is the most common type of ventricular preexcitation syndrome. […] ECG reveals a Wolff-Parkinson-White (WPW) pattern, with characteristic short PR interval and preexcitation delta wave. […] A short PR interval (less than 120 milliseconds), which reflects rapid atrioventricular (AV) conduction through an accessory pathway (the bundle of Kent) that bypasses the AV node, resulting in faster activation („preexcitation”) of the ventricles. […] A slurred QRS upstroke (delta wave), which is the result of fusion between the early ventricular activation and later activation resulting from normal AV nodal conduction. […] There are 3 main mechanisms by which tachycardia develops in patients with WPW syndrome. The first mechanism involves a reentrant circuit in which the accessory pathway conducts the impulse to the ventricles. This causes the classic wide-complex tachycardia associated with a slurred QRS upstroke, or delta wave. The second mechanism involves a reentrant circuit in which the accessory pathway conducts the impulse back to the atria. This causes a narrow-complex tachycardia–usually paroxysmal supraventricular tachycardia (PSVT). In the third mechanism, the accessory pathway is merely a „bystander” that provides an alternate route of conduction to the ventricles. This third mechanism is characteristic of a broad range of tachycardias, including atrial fibrillation. Because it causes rapid ventricular rates (faster than 200 beats per minute) that can degenerate into fibrillation and lead to sudden death, it is potentially the most life-threatening of the 3 mechanisms.

• #25 ECG Pointers: Syncope and Wolff-Parkinson-White – emDocs

  https://www.emdocs.net/ecg-pointers-syncope-and-wolf-parkinson-white/

  Patients with WPW have impulse-conducting fascicles within the atria, known as an accessory pathway (AP). This pathway results in an electrical connection between the atria and ventricles, across the annulus fibrosis, that bypasses the atrioventricular (AV) node. This pathway, referred to as the Bundle of Kent, can be located at various locations within the atria and can have numerous different histopathologic and electrophysiologic properties. Numerous other accessory pathways exist between the atria and ventricles, however these pathways have distinct histopathologic features from the Bundle of Kent and do not manifest as the typical ECG findings in WPW. Some examples of the other pathways include James fibers seen in LGL syndrome, Brechenmacher fibers, and Mahaim fibers. […] In WPW, impulses from the AP and the AV node simultaneously transmit to the ventricles, resulting in early depolarization from the AP in combination with normal depolarization through the AV node-His-Purkinje system. There is a short PR interval, which should normally represent a delay of impulse through the AV node, due to early ventricular depolarization that has bypassed the AV node. The early upstroke of the QRS, termed the delta wave, represents early ventricular depolarization that has traveled anterograde through the AP outside of the AV node-His-Purkinje system. Ventricular conduction outside of the His-Purkinje system results in early but slower depolarization of the ventricles. The remainder of the QRS is representative of normal ventricular depolarization through the AV node and the His-Purkinje system.

• #26 Wolff Parkinson White Syndrome – The Cardiology Advisor

  https://www.cancertherapyadvisor.com/home/decision-support-in-medicine/cardiology/wolff-parkinson-white-syndrome-diagnosis-and-treatment/

  Wolff Parkinson White syndrome, or WPW syndrome, is a condition that occurs when an extra electrical pathway in the heart causes a rapid heartbeat leading to congenital pre-excitation of the heart. In some cases, conduction through this accessory pathway leads to malignant tachyarrhythmias. […] The hallmark finding of Wolff Parkinson White syndrome is the electrocardiographic (ECG) finding of the delta wave. […] The initial diagnostic workup for Wolff Parkinson White syndrome includes the surface ECG. ECG findings that are associated with Wolff Parkinson White syndrome include a short PR interval (120 ms), prolonged QRS complex (120 ms), and QRS morphology that includes a slurred delta wave. […] WPW syndrome is split into type A and type B based on the direction of the dominant QRS deflection in lead V1 of the ECG.

• #27 Wolff-Parkinson-White Syndrome | Treatment & Management | Point of Care

  https://www.statpearls.com/point-of-care/31383

  WPW pattern arises from the fusion of ventricular preexcitation through the accessory pathway and normal electrical conduction through the AV node. […] This accessory pathway is thought to arise from chamber myocardium during improper early atrial and ventricular folding in cardiac embryogenesis. […] As a result, electrically conductive myocardial bundles violate the normal electrical insulation of the atrium and ventricle, forming the accessory pathway. […] WPW ECG pattern is caused by abnormal electrical conduction through an accessory pathway that bypasses the normal cardiac conduction system. […] This accessory pathway allows cardiac electrical activity to bypass the atrioventricular node conduction delay, and arrive early at the ventricle, leading to premature ventricular depolarization.

• #28 Wolff-Parkinson-White Syndrome | Treatment & Management | Point of Care

  https://www.statpearls.com/point-of-care/31383

  This preexcitation also bypasses the fast conducting His-Purkinje system and results in early but slowly propagated ventricular depolarization, which gives rise to the ECG pattern of a short PR interval with a slurred start to the QRS complex termed a delta wave. […] The pathway can either initiate and maintain an arrhythmia or allow conduction of an arrhythmia generated elsewhere. […] The other way an accessory pathway can lead to arrhythmia is by allowing conduction of an arrhythmia that is generated elsewhere to propagate to a portion of the heart that would normally be electrically insulated from this arrhythmia. […] This non-decremental conduction property predisposes patients with WPW syndrome to sudden cardiac death. […] The mechanism for deterioration to ventricular fibrillation leading to SCD is an accessory pathway that is capable of rapid antegrade conduction that allows rapid transmission of atrial impulses to the ventricle.

• #29 Wolff-Parkinson-White Syndrome: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/159222-overview

  These pathways usually exhibit different conduction properties and refractory periods that facilitate reentry. The effective refractory period (ERP, the time necessary for the electrical recovery needed to conduct the next impulse) of the accessory tract is often longer than that of the normal AV nodal His-Purkinje tract and requires time for conduction to recover before allowing reentry. […] The degree of preexcitation on a surface ECG in a person with WPW pattern can be estimated by the width of the QRS and the length of the PR interval. A wider or more preexcited QRS with a short PR interval with absent or nearly absent isoelectric component reveals that most (or all) of the ventricular depolarization initiates through the AP insertion rather than through the AV node/His Purkinje system.

• #30 Wolff-Parkinson-White Syndrome – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK554437/

  WPW ECG pattern is caused by abnormal electrical conduction through an accessory pathway that bypasses the normal cardiac conduction system. This accessory pathway allows cardiac electrical activity to bypass the atrioventricular node conduction delay, and arrive early at the ventricle, leading to premature ventricular depolarization. […] There are two ways in which an accessory pathway can lead to WPW syndrome. The pathway can either initiate and maintain an arrhythmia or allow conduction of an arrhythmia generated elsewhere. […] The other way an accessory pathway can lead to arrhythmia is by allowing conduction of an arrhythmia that is generated elsewhere to propagate to a portion of the heart that would normally be electrically insulated from this arrhythmia. […] The feared complication of WPW syndrome is sudden cardiac death (SCD). Population studies suggest that SCD is most often a result of ventricular fibrillation leading to cardiac arrest or with atrial fibrillation or circus movement tachycardia. The mechanism for deterioration to ventricular fibrillation leading to SCD is an accessory pathway that is capable of rapid antegrade conduction that allows rapid transmission of atrial impulses to the ventricle.

• #31 Wolff-Parkinson-White syndrome pathophysiology – wikidoc

  https://www.wikidoc.org/index.php/Wolff-Parkinson-White_syndrome_pathophysiology

  In normal individuals, electrical activity in the heart is initiated in the sinoatrial (SA) node (located in the right atrium), propagates to the atrioventricular (AV) node, and then through the bundle of His to the ventricles of the heart. Individuals with Wolf-parkinson-White (WPW) have an accessory pathway, known as the bundle of Kent, that communicates between the atria and the ventricles. The conduction through the accessory pathway can be bidirectional (most commonly), only retrogarde (less common), or only antegrade (least common). The most common type of tachycardia associated with WPW is atrioventricular reciprocating tachycardia (AVRT). The accessory pathway does not share the rate-slowing properties of the AV node; therefore, the combination of an accessory pathway and cardiac arrhythmia can trigger ventricular fibrillation, a leading cause of sudden cardiac death.

• #32 Wolff-Parkinson White Syndrome (WPW): Atrio-ventricular Reentry Tachycardia – AF-ABLATION

  https://af-ablation.org/en/arrhythmological-disorders/supraventricular-tachycardia/wolff-parkinson-white-syndrome-wpw-atrio-ventricular-reentry-tachycardia/

  The most common causes of re-entry SVT include nodal reentrant tachycardia (AVNRT), followed by atrioventricular reentrant tachycardia (AVRT), which depends on the presence of an accessory atrioventricular pathway (accessory pathways, AP), typical of Wolff-Parkinson-White syndrome (WPW). […] In WPW syndrome, ventricular atrium re-entry tachycardia is a macro-reentrant tachycardia that recognizes two anatomically defined conduction pathways: The Hissian node system and the accessory pathway itself. […] The accessory pathways are abnormal muscle bundles through which the electrical impulse can by-pass the physiological system by hissian node conduction. […] Pre-excitation exists when, in relation to atrial events, all or part of the ventricular muscle is activated by the atrial impulse sooner than would be expected if the impulse reached the ventricles only through the normal atrioventricular conduction system (A-V).

• #33 Wolff-Parkinson White Syndrome (WPW): Atrio-ventricular Reentry Tachycardia – AF-ABLATION

  https://af-ablation.org/en/arrhythmological-disorders/supraventricular-tachycardia/wolff-parkinson-white-syndrome-wpw-atrio-ventricular-reentry-tachycardia/

  The most common causes of re-entry SVT include nodal reentrant tachycardia (AVNRT), followed by atrioventricular reentrant tachycardia (AVRT), which depends on the presence of an accessory atrioventricular pathway (accessory pathways, AP), typical of Wolff-Parkinson-White syndrome (WPW). […] In WPW syndrome, ventricular atrium re-entry tachycardia is a macro-reentrant tachycardia that recognizes two anatomically defined conduction pathways: The Hissian node system and the accessory pathway itself. […] The accessory pathways are abnormal muscle bundles through which the electrical impulse can by-pass the physiological system by hissian node conduction. […] Pre-excitation exists when, in relation to atrial events, all or part of the ventricular muscle is activated by the atrial impulse sooner than would be expected if the impulse reached the ventricles only through the normal atrioventricular conduction system (A-V).

• #34 Pre-excitation syndromes • LITFL • ECG Library Diagnosis

  https://litfl.com/pre-excitation-syndromes-ecg-library/

  In patients with retrograde-only accessory conduction, all anterograde conduction occurs via the AV node. No pre-excitation occurs and therefore no features of WPW are seen on the ECG in sinus rhythm. This is termed a concealed pathway. These patients can still experience tachyarrhythmias, as the pathway can still form part of a re-entry circuit. […] There are only two main forms of tachyarrhythmias that occur in patients with WPW these are discussed separately: Atrial fibrillation or flutter. Due to direct conduction from atria to ventricles via an AP, bypassing the AV node, Atrioventricular re-entry tachycardia (AVRT). Due to formation of a re-entry circuit involving the AP.

• #35 Wolff-Parkinson-White Syndrome: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/159222-overview

  However, the QRS width may vary, becoming narrower during more rapid heart rates. This is possible because catecholamines permit the AV node to contribute more (or entirely) to ventricular depolarization by enhancing AV node conduction; the AV node connects to the entire and usual His-Purkinje system, resulting in the narrow QRS complex. […] In patients with WPW in which the AP participates in the reentrant circuit, 95% of SVT is due to orthodromic tachycardia and 5% is due to antidromic tachycardia.

• #36 Wolff–parkinson–white (Wpw) Syndrome | 5-Minute Emergency Consult

  https://emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307700/all/Wolff%E2%80%93parkinson%E2%80%93white__Wpw__Syndrome

  Syndrome resulting from the presence of an abnormal (accessory) pathway that bypasses the AV node (Kent bundles) between the atria and ventricles. […] WolffParkinsonWhite (WPW) pattern on the ECG is defined by a short PR interval and a -wave reflecting early conduction (pre-excitation): Accessory pathways occur in 0.10.3% of the population. […] WPW syndrome requires ECG evidence of the accessory pathway and related tachycardia. […] Conduction in WPW may be antegrade, retrograde, or both. […] Orthodromic re-entrant tachycardia is the most common (70%): Impulse travels antegrade from the atria down the AV node to the ventricle and then retrograde up the accessory pathway. […] Antidromic is less common (30%): Impulse travels antegrade down the accessory pathway and retrograde through the AV node resulting in a wide quasi-random signal (QRS) complex. […] Idiopathic: Unknown mechanism in most cases, with familial predisposition. […] Rarely inherited as an autosomal dominant trait. […] Associated in rare cases with a familial hypertrophic cardiomyopathy.

• #37 Wolff-Parkinson-White Syndrome: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/159222-overview

  These pathways usually exhibit different conduction properties and refractory periods that facilitate reentry. The effective refractory period (ERP, the time necessary for the electrical recovery needed to conduct the next impulse) of the accessory tract is often longer than that of the normal AV nodal His-Purkinje tract and requires time for conduction to recover before allowing reentry. […] The degree of preexcitation on a surface ECG in a person with WPW pattern can be estimated by the width of the QRS and the length of the PR interval. A wider or more preexcited QRS with a short PR interval with absent or nearly absent isoelectric component reveals that most (or all) of the ventricular depolarization initiates through the AP insertion rather than through the AV node/His Purkinje system.

• #38 Wolff-Parkinson-White Syndrome: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/159222-overview

  These pathways usually exhibit different conduction properties and refractory periods that facilitate reentry. The effective refractory period (ERP, the time necessary for the electrical recovery needed to conduct the next impulse) of the accessory tract is often longer than that of the normal AV nodal His-Purkinje tract and requires time for conduction to recover before allowing reentry. […] The degree of preexcitation on a surface ECG in a person with WPW pattern can be estimated by the width of the QRS and the length of the PR interval. A wider or more preexcited QRS with a short PR interval with absent or nearly absent isoelectric component reveals that most (or all) of the ventricular depolarization initiates through the AP insertion rather than through the AV node/His Purkinje system.

• #39 Wolff-Parkinson-White Syndrome: What Treatment?

  https://www.patientcareonline.com/view/wolff-parkinson-white-syndrome-what-treatment

  The most common type of tachycardia seen in WPW syndrome is PSVT, which occurs in 80% of affected patients. Atrial fibrillation occurs in 15% to 30% of patients with WPW syndrome, and atrial flutter occurs in 5%. […] Patients with the WPW pattern can be further assessed with an electrophysiology (EP) study. […] The risk factors most commonly identified include a short (less than 250 milliseconds) RR interval during atrial fibrillation, a short (less than 270 milliseconds) antegrade refractory period of the accessory pathway, and multiple accessory pathways. […] Drugs, surgery, and radiofrequency ablation have been used to prevent the recurrence of tachycardia in patients with WPW syndrome. […] Surgical ablation offers an almost 100% cure rate. However, radiofrequency ablation is less invasive, more cost-effective, and almost as successful, with cure rates ranging from 90% to 95%.

• #40 Wolff-Parkinson-White (WPW) Syndrome | Thoracic Key

  https://thoracickey.com/wolff-parkinson-white-wpw-syndrome/

  Wolff-Parkinson-White (WPW) syndrome is characterized by the presence of an accessory conduction pathway that can lead to preexcitation on the ECG. […] The mechanism of sudden death is believed to be that of rapidly conducted atrial fibrillation resulting in rapid irregular ventricular stimulation and eventually ventricular fibrillation. […] Patients with WPW are at increased risk for atrial fibrillation, even in the absence of structural heart disease. […] Therefore the risk of sudden death depends primarily on the antegrade conduction characteristics of the pathway. […] SPERRI250 ms, and especially 220 ms, is a predictor of higher risk for sudden death, and therefore an indication for prophylactic ablation.

• #41 Patient education: Wolff-Parkinson-White syndrome (Beyond the Basics) – UpToDate

  https://www.uptodate.com/contents/wolff-parkinson-white-syndrome-beyond-the-basics

  There are two mechanisms of tachycardia in the WPW syndrome: Atrioventricular reentrant tachycardia (AVRT) and Atrial fibrillation. […] The most common mechanism of tachycardia in people with WPW is called atrioventricular reentrant tachycardia (AVRT). […] During atrial fibrillation, the atria are beating in an uncoordinated manner at a rate of 350 to 600 beats per minute. […] However, with WPW, conduction from the atria to the ventricles can be rapid, resulting in more impulses getting to the ventricles by crossing the accessory pathway. […] Diagnosis of the WPW syndrome is based upon ECG evidence of the accessory pathway and the presence of a related tachycardia. […] Radiofrequency catheter ablation of the accessory pathway is the treatment of choice for people with WPW syndrome. […] When performed by experienced specialists, ablation cures the WPW syndrome over 95 percent of the time.

• #42 Patient education: Wolff-Parkinson-White syndrome (Beyond the Basics) – UpToDate

  https://www.uptodate.com/contents/wolff-parkinson-white-syndrome-beyond-the-basics

  There are two mechanisms of tachycardia in the WPW syndrome: Atrioventricular reentrant tachycardia (AVRT) and Atrial fibrillation. […] The most common mechanism of tachycardia in people with WPW is called atrioventricular reentrant tachycardia (AVRT). […] During atrial fibrillation, the atria are beating in an uncoordinated manner at a rate of 350 to 600 beats per minute. […] However, with WPW, conduction from the atria to the ventricles can be rapid, resulting in more impulses getting to the ventricles by crossing the accessory pathway. […] Diagnosis of the WPW syndrome is based upon ECG evidence of the accessory pathway and the presence of a related tachycardia. […] Radiofrequency catheter ablation of the accessory pathway is the treatment of choice for people with WPW syndrome. […] When performed by experienced specialists, ablation cures the WPW syndrome over 95 percent of the time.

• #43 Wolff-Parkinson-White syndrome pathophysiology – wikidoc

  https://www.wikidoc.org/index.php/Wolff-Parkinson-White_syndrome_pathophysiology

  The conduction through the accessory pathway can be bidirectional (most commonly): retrogarde (also known as concealed) as well as antegrade (also known as manifest, responsible for the ECG findings of delta wave and short PR interval). […] The most common type of tachycardia associated with WPW is atrioventricular reciprocating tachycardia (AVRT). […] The accessory pathway does not share the rate-slowing properties of the AV node, and may conduct electrical activity at a significantly higher rate than the AV node. […] The combination of an accessory pathway and tachyarrhythmia can trigger ventricular fibrillation and sudden cardiac death. […] The missense Mutation in PKRAG2 has been associated with the development of familiar WPW syndrome and cardiac hypertrophy, involving the gamma-2 subunit of AMPK pathway.

• #44 Wolff-Parkinson-White syndrome pathophysiology – wikidoc

  https://www.wikidoc.org/index.php/Wolff-Parkinson-White_syndrome_pathophysiology

  The conduction through the accessory pathway can be bidirectional (most commonly): retrogarde (also known as concealed) as well as antegrade (also known as manifest, responsible for the ECG findings of delta wave and short PR interval). […] The most common type of tachycardia associated with WPW is atrioventricular reciprocating tachycardia (AVRT). […] The accessory pathway does not share the rate-slowing properties of the AV node, and may conduct electrical activity at a significantly higher rate than the AV node. […] The combination of an accessory pathway and tachyarrhythmia can trigger ventricular fibrillation and sudden cardiac death. […] The missense Mutation in PKRAG2 has been associated with the development of familiar WPW syndrome and cardiac hypertrophy, involving the gamma-2 subunit of AMPK pathway.

• #45 Wolff-Parkinson-White Syndrome | Treatment & Management | Point of Care

  https://www.statpearls.com/point-of-care/31383

  This preexcitation also bypasses the fast conducting His-Purkinje system and results in early but slowly propagated ventricular depolarization, which gives rise to the ECG pattern of a short PR interval with a slurred start to the QRS complex termed a delta wave. […] The pathway can either initiate and maintain an arrhythmia or allow conduction of an arrhythmia generated elsewhere. […] The other way an accessory pathway can lead to arrhythmia is by allowing conduction of an arrhythmia that is generated elsewhere to propagate to a portion of the heart that would normally be electrically insulated from this arrhythmia. […] This non-decremental conduction property predisposes patients with WPW syndrome to sudden cardiac death. […] The mechanism for deterioration to ventricular fibrillation leading to SCD is an accessory pathway that is capable of rapid antegrade conduction that allows rapid transmission of atrial impulses to the ventricle.

• #46 Wolff-Parkinson-White Syndrome | Treatment & Management | Point of Care

  https://www.statpearls.com/point-of-care/31383

  This preexcitation also bypasses the fast conducting His-Purkinje system and results in early but slowly propagated ventricular depolarization, which gives rise to the ECG pattern of a short PR interval with a slurred start to the QRS complex termed a delta wave. […] The pathway can either initiate and maintain an arrhythmia or allow conduction of an arrhythmia generated elsewhere. […] The other way an accessory pathway can lead to arrhythmia is by allowing conduction of an arrhythmia that is generated elsewhere to propagate to a portion of the heart that would normally be electrically insulated from this arrhythmia. […] This non-decremental conduction property predisposes patients with WPW syndrome to sudden cardiac death. […] The mechanism for deterioration to ventricular fibrillation leading to SCD is an accessory pathway that is capable of rapid antegrade conduction that allows rapid transmission of atrial impulses to the ventricle.

• #47 Wolff-Parkinson-White Syndrome: What Treatment?

  https://www.patientcareonline.com/view/wolff-parkinson-white-syndrome-what-treatment

  WPW syndrome is the most common type of ventricular preexcitation syndrome. […] ECG reveals a Wolff-Parkinson-White (WPW) pattern, with characteristic short PR interval and preexcitation delta wave. […] A short PR interval (less than 120 milliseconds), which reflects rapid atrioventricular (AV) conduction through an accessory pathway (the bundle of Kent) that bypasses the AV node, resulting in faster activation („preexcitation”) of the ventricles. […] A slurred QRS upstroke (delta wave), which is the result of fusion between the early ventricular activation and later activation resulting from normal AV nodal conduction. […] There are 3 main mechanisms by which tachycardia develops in patients with WPW syndrome. The first mechanism involves a reentrant circuit in which the accessory pathway conducts the impulse to the ventricles. This causes the classic wide-complex tachycardia associated with a slurred QRS upstroke, or delta wave. The second mechanism involves a reentrant circuit in which the accessory pathway conducts the impulse back to the atria. This causes a narrow-complex tachycardia–usually paroxysmal supraventricular tachycardia (PSVT). In the third mechanism, the accessory pathway is merely a „bystander” that provides an alternate route of conduction to the ventricles. This third mechanism is characteristic of a broad range of tachycardias, including atrial fibrillation. Because it causes rapid ventricular rates (faster than 200 beats per minute) that can degenerate into fibrillation and lead to sudden death, it is potentially the most life-threatening of the 3 mechanisms.

• #48 Wolff-Parkinson-White syndrome: Diagnostic and management strategies | Cleveland Clinic Journal of Medicine

  https://www.ccjm.org/content/92/2/119

  An unknown number of people are born with single or multiple accessory electrical pathways between the atria and the ventricles. […] WPW syndrome is a rare congenital cardiac condition in which the patient has single or multiple accessory pathways along the atrioventricular border that predispose them to potentially malignant tachyarrhythmias. […] The accessory pathway makes patients vulnerable to 2 forms of arrhythmia: Reentrant arrhythmias such as reentrant supraventricular tachycardia, when impulses travel down the atrioventricular node and then retrograde (up) through the accessory pathway […] Accelerated conduction of atrial arrhythmias, as the accessory pathway, unlike the atrioventricular node, does not delay the electrical impulse. […] WPW pattern is diagnosed in patients who have no symptoms but who do have the aforementioned electrocardiographic signs, while a diagnosis of WPW syndrome means the patient has a WPW pattern and symptoms related to arrhythmias caused by the accessory pathway.

• #49 Wolff-Parkinson-White Syndrome – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK554437/

  WPW ECG pattern is caused by abnormal electrical conduction through an accessory pathway that bypasses the normal cardiac conduction system. This accessory pathway allows cardiac electrical activity to bypass the atrioventricular node conduction delay, and arrive early at the ventricle, leading to premature ventricular depolarization. […] There are two ways in which an accessory pathway can lead to WPW syndrome. The pathway can either initiate and maintain an arrhythmia or allow conduction of an arrhythmia generated elsewhere. […] The other way an accessory pathway can lead to arrhythmia is by allowing conduction of an arrhythmia that is generated elsewhere to propagate to a portion of the heart that would normally be electrically insulated from this arrhythmia. […] The feared complication of WPW syndrome is sudden cardiac death (SCD). Population studies suggest that SCD is most often a result of ventricular fibrillation leading to cardiac arrest or with atrial fibrillation or circus movement tachycardia. The mechanism for deterioration to ventricular fibrillation leading to SCD is an accessory pathway that is capable of rapid antegrade conduction that allows rapid transmission of atrial impulses to the ventricle.

• #50

  https://journals.lww.com/md-journal/fulltext/2018/12210/sudden_cardiac_death_due_to_the.8.aspx

  The WolffParkinsonWhite syndrome (WPW) is a benign heart disease with accessory pathways, which can result in cardiac arrhythmias. […] Diagnosis of WPW syndrome is based on typical electrocardiogram findings with a documented dysrhythmia before the victim’s death. […] The overall risk of SCD in the WPW syndrome is estimated at 0.1% in asymptomatic patients and 0.3% in symptomatic patients per year. […] The clinical history of tachycardia, palpitation and ventricular pre-excitation, and ECG finding indicated that he had arrhythmic symptoms accompanied by WPW syndrome. […] Thus, it was presumed that the cause of death was SCD, although without lethal structural abnormality. Moreover, WPW with arrhythmias accounted for the death. […] The most common arrhythmia in WPW patients is atrioventricular re-entrant tachycardia, which occurs in 80% of cases.

• #51

  https://journals.lww.com/md-journal/fulltext/2018/12210/sudden_cardiac_death_due_to_the.8.aspx

  Ventricular fibrillation is the most common cause of sudden death in WPW patients. […] Risk factors for SCD in patients with WPW syndrome are localization of the accessory pathway, emotional or physical stress, additional cardiac structural abnormalities and accompanying symptoms. […] In the presence of the myocardial bridge, myocardial ischemia is more serious when arrhythmias occur. […] This case highlights that SCD can occur in WPW patients with mild or unrecognized structural abnormality. […] In addition, the deceased with WPW syndrome have accessory atrio-ventricular connections in the heart anatomy, but the cardiac autopsy cannot provide a standardized demonstration of accessory pathways at the histological assessment.

• #52

  https://journals.lww.com/md-journal/fulltext/2018/12210/sudden_cardiac_death_due_to_the.8.aspx

  Ventricular fibrillation is the most common cause of sudden death in WPW patients. […] Risk factors for SCD in patients with WPW syndrome are localization of the accessory pathway, emotional or physical stress, additional cardiac structural abnormalities and accompanying symptoms. […] In the presence of the myocardial bridge, myocardial ischemia is more serious when arrhythmias occur. […] This case highlights that SCD can occur in WPW patients with mild or unrecognized structural abnormality. […] In addition, the deceased with WPW syndrome have accessory atrio-ventricular connections in the heart anatomy, but the cardiac autopsy cannot provide a standardized demonstration of accessory pathways at the histological assessment.

• #53 Wolff-Parkinson-White (WPW) Syndrome | Thoracic Key

  https://thoracickey.com/wolff-parkinson-white-wpw-syndrome/

  Wolff-Parkinson-White (WPW) syndrome is characterized by the presence of an accessory conduction pathway that can lead to preexcitation on the ECG. […] The mechanism of sudden death is believed to be that of rapidly conducted atrial fibrillation resulting in rapid irregular ventricular stimulation and eventually ventricular fibrillation. […] Patients with WPW are at increased risk for atrial fibrillation, even in the absence of structural heart disease. […] Therefore the risk of sudden death depends primarily on the antegrade conduction characteristics of the pathway. […] SPERRI250 ms, and especially 220 ms, is a predictor of higher risk for sudden death, and therefore an indication for prophylactic ablation.

• #54 Iatrogenic ventricular fibrillation in Wolff-Parkinson-White syndrome | Revista Portuguesa de Cardiologia

  https://www.revportcardiol.org/pt-iatrogenic-ventricular-fibrillation-in-wolff-parkinson-white-articulo-S0870255122003663

  Wolff-Parkinson-White (WPW) syndrome is the most common manifestation of ventricular pre-excitation syndrome and is mostly found in individuals with no structural heart disease. […] Although the risk of malignant arrhythmias is low, sudden cardiac death (SCD) as the first clinical manifestation of WPW syndrome is well documented, and atrial fibrillation (AF) with a rapid ventricular response is the main mechanism involved. […] Blocking the AV node in patients with pre-excited AF may increase the ventricular rate and potentially result in hemodynamic instability. […] Among patients with WPW syndrome who survive an episode of SCD, catheter ablation of the accessory pathway is the treatment of choice. […] Wolff-Parkinson-White (WPW) syndrome refers to the association of manifest pre-excitation and symptoms due to reentrant arrhythmias. The risk of malignant arrhythmias is low but sudden cardiac death (SCD) may be the first manifestation of this condition.

• #55 Iatrogenic ventricular fibrillation in Wolff-Parkinson-White syndrome | Revista Portuguesa de Cardiologia

  https://www.revportcardiol.org/pt-iatrogenic-ventricular-fibrillation-in-wolff-parkinson-white-articulo-S0870255122003663

  In patients with an AP capable of anterograde conduction who develop AF, conduction to the ventricle often occurs through a combination of the normal conduction pathway (via the AV node) and the AP. […] However, because most APs have a shorter refractory period than the AV node, the ventricular rate can be more rapid if AV conduction occurs preferentially via the AP. […] Hence, AV nodal blocking drugs (adenosine, verapamil, beta-blockers, and digoxin) should be avoided in patients with pre-excited AF, since blocking the AV node will promote conduction down the AP, lengthening AV node refractoriness, and may sometimes directly increase the rate of conduction over the AP. […] Our case illustrates an example of an iatrogenic malignant arrhythmia in a WPW patient presenting with a pre-excited AF that was neither promptly diagnosed nor properly treated.

• #56

  https://step2.medbullets.com/cardiovascular/121718/wolff-parkinson-white-wpw-syndrome

  ventricular pre-excitation results from an aberrant conduction tract from the atria to the ventricle, known as the bundle of Kent […] this fast accessory tract bypasses the slowest-conducting AV node […] ventricles then depolarize earlier than normal […] this causes the classic delta wave and widened QRS […] administration of calcium channel blockers or digoxin will worsen a supraventricular tachycardia (SVT) caused by WPW syndrome […] calcium channel blockers and digoxin block conduction in the AV node and will force more conduction down the aberrant tract, worsening WPW syndrome.

• #57 Wolff-Parkinson-White syndrome: Diagnostic and management strategies | Cleveland Clinic Journal of Medicine

  https://www.ccjm.org/content/92/2/119

  WPW syndrome affects an estimated 1 to 3 individuals per 1,000 worldwide. […] The most severe and feared complication is sudden cardiac death, owing to the rapid atrial rates in atrial fibrillation that are transmitted directly to the ventricles by the accessory pathway, causing ventricular fibrillation. […] Catheter ablation has a class I (strong) recommendation in patients who have symptoms and the WPW pattern (WPW syndrome). […] More electrophysiologists now than in the past may be performing electrophysiologic studies in patients with an asymptomatic WPW pattern regardless of noninvasive findings. […] Given the low risk and potential for a permanent cure via catheter ablation, there is an incentive to identify and manage WPW syndrome proactively.

• #58 Patient education: Wolff-Parkinson-White syndrome (Beyond the Basics) – UpToDate

  https://www.uptodate.com/contents/wolff-parkinson-white-syndrome-beyond-the-basics

  There are two mechanisms of tachycardia in the WPW syndrome: Atrioventricular reentrant tachycardia (AVRT) and Atrial fibrillation. […] The most common mechanism of tachycardia in people with WPW is called atrioventricular reentrant tachycardia (AVRT). […] During atrial fibrillation, the atria are beating in an uncoordinated manner at a rate of 350 to 600 beats per minute. […] However, with WPW, conduction from the atria to the ventricles can be rapid, resulting in more impulses getting to the ventricles by crossing the accessory pathway. […] Diagnosis of the WPW syndrome is based upon ECG evidence of the accessory pathway and the presence of a related tachycardia. […] Radiofrequency catheter ablation of the accessory pathway is the treatment of choice for people with WPW syndrome. […] When performed by experienced specialists, ablation cures the WPW syndrome over 95 percent of the time.

• #59 Wolf–Parkinson–White Syndrome: Diagnosis, Risk Assessment, and Therapy—An Update

  https://www.mdpi.com/2075-4418/14/3/296

  Management of asymptomatic patients with WPW patterns has always been controversial because asymptomatic does not preclude sudden cardiac death. […] RFA has completely revolutionized the approach to the management of WPW syndrome, becoming the method of choice potentially available to all WPW patients. […] In the long term, successful WPW ablation is associated with reduced mortality (due to SCD prevention, as well as reduced risk of heart failure).

• #60 Wolf–Parkinson–White Syndrome: Diagnosis, Risk Assessment, and Therapy—An Update

  https://www.mdpi.com/2075-4418/14/3/296

  Management of asymptomatic patients with WPW patterns has always been controversial because asymptomatic does not preclude sudden cardiac death. […] RFA has completely revolutionized the approach to the management of WPW syndrome, becoming the method of choice potentially available to all WPW patients. […] In the long term, successful WPW ablation is associated with reduced mortality (due to SCD prevention, as well as reduced risk of heart failure).

• #61 Wolff-Parkinson-White syndrome | Better Health Channel

  https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/wolff-parkinson-white-syndrome

  An electrophysiology study to locate the site of the extra pathway and eliminate it, using a short treatment with radio frequency energy, applied through a catheter. […] Removing the extra pathway, via catheterisation, usually cures the disorder. […] If it cannot be found or eliminated safely then long-term medication may be necessary or surgery might be recommended.

• #62 Wolff-Parkinson-White Syndrome: What Treatment?

  https://www.patientcareonline.com/view/wolff-parkinson-white-syndrome-what-treatment

  The most common type of tachycardia seen in WPW syndrome is PSVT, which occurs in 80% of affected patients. Atrial fibrillation occurs in 15% to 30% of patients with WPW syndrome, and atrial flutter occurs in 5%. […] Patients with the WPW pattern can be further assessed with an electrophysiology (EP) study. […] The risk factors most commonly identified include a short (less than 250 milliseconds) RR interval during atrial fibrillation, a short (less than 270 milliseconds) antegrade refractory period of the accessory pathway, and multiple accessory pathways. […] Drugs, surgery, and radiofrequency ablation have been used to prevent the recurrence of tachycardia in patients with WPW syndrome. […] Surgical ablation offers an almost 100% cure rate. However, radiofrequency ablation is less invasive, more cost-effective, and almost as successful, with cure rates ranging from 90% to 95%.

• #63 Wolff Parkinson White Syndrome: Which Best Perioperative Strategy?

  https://www.gavinpublishers.com/article/view/wolff-parkinson-white-syndrome-which-best-perioperative-strategy

  This determines that depolarization impulses from the atria can reach the ventricles via both pathways resulting in three features of abnormal electrical conduction: a short PR interval (less than 0.12 seconds), Pre-excitation or delta wave, and a widened QRS-wave. […] Traditionally, WPW is classified in type A and B. […] It must be considered that not always these electric characteristics are present: a delta wave may not be apparent according to the duration of the refractory period of the AP as well as some APs may only conduct in a retrograde manner participating in re-entrant arrhythmias with a normal ECG showing a sinus rhythm without a WPW pattern. […] 20% of WPW syndromic patients present with atrial fibrillation or flutter while the remaining majority present an atrioventricular re-entrant tachycardia (AVRT) that can be either orthodromic or antidromic.

• #64 Wolff–Parkinson–White syndrome – Wikipedia

  https://en.wikipedia.org/wiki/Wolff%E2%80%93Parkinson%E2%80%93White_syndrome

  WPW may be associated with PRKAG2, a protein kinase enzyme encoded by the PRKAG2 gene. […] The bundle of Kent is an abnormal extra or accessory conduction pathway between the atria and ventricles that is present in a small percentage (between 0.1 and 0.3%) of the general population. […] This pathway may communicate between the left atrium and the left ventricle, in which case it is termed a „type A pre-excitation”, or between the right atrium and the right ventricle, in which case it is termed a „type B pre-excitation” in old, currently abandoned classification. […] The AV node is capable of slowing the rate of conduction of electrical impulses to the ventricles, whereas the bundle of Kent lacks this capability.

• #65 Wolff–Parkinson–White syndrome – Wikipedia

  https://en.wikipedia.org/wiki/Wolff%E2%80%93Parkinson%E2%80%93White_syndrome

  WPW may be associated with PRKAG2, a protein kinase enzyme encoded by the PRKAG2 gene. […] The bundle of Kent is an abnormal extra or accessory conduction pathway between the atria and ventricles that is present in a small percentage (between 0.1 and 0.3%) of the general population. […] This pathway may communicate between the left atrium and the left ventricle, in which case it is termed a „type A pre-excitation”, or between the right atrium and the right ventricle, in which case it is termed a „type B pre-excitation” in old, currently abandoned classification. […] The AV node is capable of slowing the rate of conduction of electrical impulses to the ventricles, whereas the bundle of Kent lacks this capability.

• #66 Wolff Parkinson White Syndrome – The Cardiology Advisor

  https://www.cancertherapyadvisor.com/home/decision-support-in-medicine/cardiology/wolff-parkinson-white-syndrome-diagnosis-and-treatment/

  Wolff Parkinson White syndrome, or WPW syndrome, is a condition that occurs when an extra electrical pathway in the heart causes a rapid heartbeat leading to congenital pre-excitation of the heart. In some cases, conduction through this accessory pathway leads to malignant tachyarrhythmias. […] The hallmark finding of Wolff Parkinson White syndrome is the electrocardiographic (ECG) finding of the delta wave. […] The initial diagnostic workup for Wolff Parkinson White syndrome includes the surface ECG. ECG findings that are associated with Wolff Parkinson White syndrome include a short PR interval (120 ms), prolonged QRS complex (120 ms), and QRS morphology that includes a slurred delta wave. […] WPW syndrome is split into type A and type B based on the direction of the dominant QRS deflection in lead V1 of the ECG.

• #67 Pre-excitation syndromes • LITFL • ECG Library Diagnosis

  https://litfl.com/pre-excitation-syndromes-ecg-library/

  WPW Syndrome refers to the presence of a congenital accessory pathway (AP) and episodes of tachyarrhythmias. The term is often used interchangeablely with pre-excitation syndrome […] Pre-excitation refers to early activation of the ventricles due to impulses bypassing the AV node via an AP. Also known as bypass tracts, APs are abnormal conduction pathways formed during cardiac development and can exist in a variety of anatomical locations and in some patients there may be multiple pathways. In WPW, the AP is sometimes referred to as the Bundle of Kent, or atrioventricular bypass tract. […] An AP can conduct impulses in three ways: In both directions (majority), Retrograde only, away from the ventricle (15%), Anterograde only, towards the ventricle (rare). […] The direction of conduction affects the appearance of the ECG in sinus rhythm and during tachyarrhythmias.

• #68 Pre-excitation syndromes • LITFL • ECG Library Diagnosis

  https://litfl.com/pre-excitation-syndromes-ecg-library/

  In patients with retrograde-only accessory conduction, all anterograde conduction occurs via the AV node. No pre-excitation occurs and therefore no features of WPW are seen on the ECG in sinus rhythm. This is termed a concealed pathway. These patients can still experience tachyarrhythmias, as the pathway can still form part of a re-entry circuit. […] There are only two main forms of tachyarrhythmias that occur in patients with WPW these are discussed separately: Atrial fibrillation or flutter. Due to direct conduction from atria to ventricles via an AP, bypassing the AV node, Atrioventricular re-entry tachycardia (AVRT). Due to formation of a re-entry circuit involving the AP.

• #69 Wolff-Parkinson-White (WPW) Syndrome: Symptoms and Causes

  https://lonestarneurology.net/blog/wolff-parkinson-white-syndrome/

  Wolff-Parkinson-White syndrome is a violation of the process of excitation of the ventricles, in which there is an increase in the heart rate. […] With this pathology, secondary conduction pathways are formed, called the Kent beam, which is characterized by different electrophysiological properties and therefore conducts excitation faster. In this case, the wave of depolarization propagates in different directions from the atria to the ventricles and is called a delta wave. As a result, premature excitation and contraction of the ventricles occur. […] These diseases disrupt the normal structure of the heart and the proper functioning of the conducting system. And tachyarrhythmias provoke a decrease in myocardial contractility and expansion of the atria and ventricles. […] The main types of this syndrome are: Manifest WPW syndrome is established in patients with delta wave ECG and tachyarrhythmias. The most common arrhythmia among patients with WPW syndrome is atrioventricular reciprocal tachycardia (AVRT). The term reciprocal is synonymous with the term re-entry the mechanism of tachycardia.

• #70 Atrio-Ventricular Abnormalities (WPW) Ablation – AF-ABLATION

  https://af-ablation.org/en/arrythmological-procedures-and-therapies/transcatheter-ablation/atrio-ventricular-abnormalities-wpw-ablation/

  The criteria used to identify the appropriate target sites for the ablation of the hidden pathway include the presence of retrograde potential along the accessory pathway, continuous retrograde electrical activity with ventricular stimulation or during tachycardia and electrogram stability. […] In about 10-15% of subjects with pre-excitation, there are multiple accessory pathways. Histopathological data show a higher frequency of multiple accessory pathways than those observed clinically. The presence of multiple accessory pathways increases the incidence of symptoms and is associated with a higher risk of sudden death due to atrial fibrillation that degenerates into ventricular fibrillation. […] Currently, the importance of electrophysiological study (EP) and transcatheter ablation of accessory pathways are well established in symptomatic patients with WPW syndrome. Based on the recommendations of the 2019 ACC / AHA / ESC guidelines, in the case of symptomatic pre-excitation, transcatheter ablation has a class I indication.

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