Materiały źródłowe

• #1 Atrioventricular Block – Cardiovascular Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/cardiovascular-disorders/specific-cardiac-arrhythmias/atrioventricular-block

  Atrioventricular (AV) block is partial or complete interruption of impulse transmission from the atria to the ventricles. Diagnosis is by electrocardiography; symptoms and treatment depend on degree of block, but treatment, when necessary, usually involves pacing. […] Up to one-third of patients age 18 years to 60 years with new-onset Mobitz II second-degree or third-degree AV block without evident structural heart disease are diagnosed with cardiac sarcoidosis after targeted investigations. […] Further investigation may be indicated when first-degree AV block accompanies another heart disorder or appears to be caused by medication. […] Patients with any form of second-degree AV block and a structural heart disorder should be considered candidates for permanent pacing unless there is a transient or reversible cause.

• #2 Atrioventricular Block > Fact Sheets > Yale Medicine

  https://www.yalemedicine.org/conditions/atrioventricular-block

  Atrioventricular block is a heart rhythm disorder that causes the heart to beat more slowly than it should. Its caused by communication problems within the hearts electrical conduction system. For some people, the condition doesnt cause symptoms; for others, it may be life-threatening. […] Atrioventricular block is the medical term for a slowed heart rate that occurs because of a malfunction with the hearts electrical system. There are varying degrees of atrioventricular block, some which are so mild they go undetected and some so severe they may be life-threatening. […] People with second- or third-degree atrioventricular block may see their doctor to discuss the symptoms they are experiencing. They may be diagnosed after discussing their medical history, getting a physical examination, and having various diagnostic tests.

• #3 Heart Block: Types, Symptoms & Causes

  https://my.clevelandclinic.org/health/diseases/17056-heart-block

  Heart block is a problem with your heartbeat signal moving from the upper to lower part of your heart. The signal can only get through sometimes, or not at all. This makes your heart beat slowly or skip beats. People with second-degree or third-degree heart block may experience fainting, tiredness and shortness of breath. […] Heart block keeps heartbeat signals from reaching your hearts lower chambers on time, every time or at all. […] If you have heart block, the signal only makes it to your ventricles some of the time, if at all. […] To diagnose heart block, your healthcare provider will: Review your medical history. Review your biological familys health history. Ask questions about your overall health, eating habits, physical activity level and symptoms. Ask you about any medications youre taking (prescription or over the counter). Ask you if you smoke or use recreational drugs. Listen to your heart and check your heart rate. Check for signs of heart failure, like fluid buildup in your feet, ankles and legs.

• #4 Heart Block: Causes, Symptoms, Diagnosis and Treatment | Max Lab

  https://www.maxlab.co.in/blogs/heart-block-causes-symptoms-diagnosis-treatment

  The heart’s rhythmic beatings rely on electrical signals that coordinate contractions between its upper and lower chambers, also known as, atria and ventricles. However, in heart block, these signals are disrupted, causing the heart to beat too slowly to pump blood effectively. […] Before recommending any test for heart blockage diagnosis, a cardiologist will first examine the medical history of individuals and the medicines they are taking. The cardiologist also reviews the diet, physical activity, lifestyle, and overall health of individuals. Then, a physical examination is conducted in which the doctor checks the heart rate and signs of heart failure. For further understanding of the symptoms, some tests for heart blockage are recommended that include the following: […] ECG: It is a non-invasive test to evaluate the heart’s rhythm, strength, and rate by placing electrodes at certain spots, including the chest, legs, and arm. An ECG or electrocardiogram helps in first or second-degree heart block diagnosis.

• #5 Atrioventricular Block > Fact Sheets > Yale Medicine

  https://www.yalemedicine.org/conditions/atrioventricular-block

  When doctors suspect atrioventricular block, they may recommend the following tests: An electrocardiogram, which tracks the hearts electrical activity. A patient with atrioventricular block wont have normal heart wave patterns; the study may show other abnormalities associated with atrioventricular block. […] During a physical exam, doctors may notice that patients have a slower-than-normal heart rate (bradycardia) or low blood pressure. […] Some types of atrioventricular block are reversible, particularly when they are caused by underlying conditions. For the types of atrioventricular block that are not reversible, the condition is very treatable with procedures such as pacemaker implantation. Helping the heart rhythm return to a more normal rate should help people manage the condition and avoid symptoms or other severe downstream consequences such as cardiac arrest.

• #6 Heart block

  https://www.nhs.uk/conditions/heart-block/

  The main test used to diagnose heart block is an electrocardiogram (ECG), which measures the electrical activity of your heart. […] Other tests that may be used to help diagnose heart block include: an echocardiogram or MRI scan to get a picture of your heart and the nearby blood vessels, exercise tests to check your heart while you use a bike or treadmill, blood tests.

• #7 Heart Block: Symptoms and Diagnosis | Dr Lal PathLabs Blogs

  https://www.lalpathlabs.com/blog/heart-block/

  How to diagnose heart block? […] You can undergo an electrocardiogram (ECG) test to check the electrical activity of your heart. Electrodes are connected to your heart, and the electrocardiogram machine records the hearts activity.

• #8 Heart Block: Types, Symptoms & Causes

  https://my.clevelandclinic.org/health/diseases/17056-heart-block

  Your cardiologist may refer you to an electrophysiologist, an expert in the electrical activity of your heart. […] Tests you might have include: Blood tests. Genetic tests. Electrocardiogram (EKG). Ambulatory monitor. Loop recorder. Electrophysiology study. Exercise stress test. […] Heart block treatment varies from person to person. A provider may admit you to the hospital to monitor your heart. To manage your condition, your cardiologist will consider: Which type of heart block you have. The severity of your heart block. How it affects your hearts ability to function. The symptoms youre having. […] Sometimes, making changes to medicines or treatment for heart disease stops heart block. Other people may need a temporary or permanent pacemaker that sends electrical pulses to their hearts.

• #9 Third-Degree Atrioventricular Block (Complete Heart Block) Workup: Laboratory Studies, Imaging Studies, Electrocardiography

  https://emedicine.medscape.com/article/162007-workup

  For most patients with illness serious enough to cause third-degree atrioventricular (AV) block (complete heart block), a complete blood cell (CBC) count is indicated to screen for coincident problems (eg, anemia, infection) that may require emergency intervention. […] The most important study in patients with suspected third-degree atrioventricular (AV) block (complete heart block) is 12-lead electrocardiography (ECG). On 12-lead ECG, third-degree AV block is characterized by complete lack of conduction (no P waves cause a QRS complex). […] If the patient’s clinical history or 12-lead electrocardiographic (ECG) findings suggest active coronary artery disease, then measurement of cardiac enzyme levels and an evaluation of ischemia, including either cardiac catheterization or stress testing, are needed. […] Diagnostic electrophysiologic studies can be performed to assess atrioventricular (AV) conduction and to discern the level of block (AV nodal or infranodal) when necessary.

• #10 ECG Diagnosis: Complete Heart Block

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3140757/

  Third-degree atrioventricular (AV) block (also referred to as complete heart block) is the complete dissociation of the atria and the ventricles. Third-degree AV block exists when more P waves than QRS complexes exist and no relationship (no conduction) exists between them. The escape rhythm may arise within the AV node (resulting in a narrow QRS complex), or lower in the conduction system (producing a wide QRS complex). The ventricular rate (pulse) varies from 30-40 beats/minute. Characteristically in third-degree AV block, the atrial rate is faster than the ventricular rate (60-100 beats/minute) presumably in response to the hemodynamic consequences of the block. Complete heart block complicates 10% of acute myocardial infarctions (AMI) and represents the most frequent unstable bradydysrhythmia encountered in the patient with AMI. In most cases of persistent third-degree AV block, permanent pacing is required. Treatment with atropine often fails to improve the ventricular rate, as vagal stimulation of the AV node is not thought to be the cause of this finding.

• #11 AV block: 3rd degree (complete heart block) • LITFL • ECG Library

  https://litfl.com/av-block-3rd-degree-complete-heart-block/

  Severe bradycardia due to absence of AV conduction. […] The ECG demonstrates complete AV dissociation, with independent atrial and ventricular rates. […] In complete heart block, there is complete absence of AV conduction, with none of the supraventricular impulses conducted to the ventricles. […] Patients with third degree heart block are at high risk of ventricular standstill and sudden cardiac death. […] They require urgent admission for cardiac monitoring, backup temporary pacing and usually insertion of a permanent pacemaker. […] Complete heart block should not be confused with high grade AV block: A type of severe second degree heart block with a very slow ventricular rate but still some evidence of occasional AV conduction. […] None of the atrial impulses appear to be conducted to the ventricles. […] This confirms that the atrial impulses are not being conducted to the ventricles.

• #12 Third-Degree Atrioventricular Block (Complete Heart Block): Background, Pathophysiology, Etiology

  https://emedicine.medscape.com/article/162007-overview

  Third-degree atrioventricular (AV) block, also referred to as third-degree heart block or complete heart block (CHB), is an abnormal heart rhythm resulting from a defect in the cardiac conduction system in which there is no conduction through the atrioventricular node (AVN), leading to complete dissociation of the atria and ventricles. The ventricular escape mechanism can occur anywhere from the AVN to the bundle-branch Purkinje system. […] Third-degree AV block is electrocardiographically characterized by: Regular P-P interval, Regular R-R interval, Lack of an apparent relationship between the P waves and QRS complexes, More P waves are present than QRS complexes. […] Note that not all patients with AV dissociation have complete heart block. For example, patients with ventricular tachycardia have AV dissociation, but not complete heart block; in this example, AV dissociation is due to the ventricular rate being faster than the intrinsic sinus rate.

• #13 Heart Block | Conditions | UCSF Health

  https://www.ucsfhealth.org/conditions/heart-block

  In addition to asking questions about your health history and performing a physical exam, your doctor may order one or more of the following tests: […] Electrocardiogram (ECG or EKG). By recording the heart’s electrical activity, the ECG helps doctors diagnose arrhythmias (problems with heart rhythm) and heart damage. […] Holter monitor. A Holter monitor is a small, portable device that continuously records your heart rhythms as you go about your daily activities. You’ll need to wear it for one to two days. A Holter monitor can detect heart rhythm problems that aren’t caught by a short ECG test. […] Event monitor. This small device may be worn for several weeks. You activate it to record your heart rate and rhythm whenever you feel symptoms. Event recorders are good for patients who don’t experience symptoms frequently. […] Electrophysiology (EP) study. This minimally invasive procedure allows doctors to assess your heart’s electrical system and activity.

• #14 Heart Block – Paces

  https://www.pacesep.org/patient-resources/heart-block/

  The diagnosis of heart block is based on the relationship between the P-wave, which is the signal coming from the sinus node, and the QRS complex, which is the electrical response in the ventricles. […] The diagnosis of heart block is made based on specific findings noted on your electrocardiogram (ECG). Specifically, your healthcare team will look at the relationship between the electrical signals from the top of the heart and the electrical signals in the bottom of the heart. […] After a diagnosis of heart block has been made, your healthcare team may order additional testing. This may include a long-term monitor such as a Holter monitor to determine the frequency and severity of the heart block. Holters or other long-term monitors may be worn again for routine rhythm monitoring, or if there is a concern about worsening heart block or symptoms. […] Another common test after the diagnosis of heart block is an exercise stress test.

• #15 Heart Block: Causes, Symptoms, Diagnosis and Treatment | Max Lab

  https://www.maxlab.co.in/blogs/heart-block-causes-symptoms-diagnosis-treatment

  Implantable Loop Recorder: This is a medical device injected under the chest skin to monitor the heart rhythm. It can be used for up to three to five years so the cardiologist can know how well the person’s heart functions while doing their daily activities. […] Electrophysiology Study: It is another important test for checking heart blockage by studying the heart’s electrical system and if the heart is beating abnormally. During the procedure, a catheter, a long thin tube, is inserted into the heart through a blood vessel to evaluate the electrical activity.

• #16 Heart Block: Diagnosis & Treatment | NewYork-Presbyterian

  https://www.nyp.org/heart/arrhythmias/heart-block/treatment

  How is Heart Block Diagnosed? Diagnosis If you or your physician suspects you may be suffering from heart block, your doctor will likely begin by discussing your personal and family medical history with you. They will talk with you about any symptoms youre experiencing, any other conditions you have, and medications you may be taking. Heart block is usually diagnosed with one or more tests, which can include: […] Electrocardiogram (ECG) – An ECG records the heart’s electric impulses and can give your doctor information about its rhythm, size, and any possible damage […] Implantable loop recorder – A small device injected into the chest that can monitor the heart’s rhythm for up to several years. An implant loop recorder can provide information about the heart over a long period. […] Electrophysiology (EP) study – A minimally invasive procedure during which catheters are inserted into a vein or artery to record electrical impulses from the heart.

• #17

  https://www.virginiaheart.com/for-patients/about-your-diagnosis/heart-block

  Holter Monitor- This device records the heart’s activity for 24 hours or longer. […] Event recorder- This portable ECG can be activated when a patient experiences symptoms of a fast heart rate. […] Implantable loop recorder- This implanted recorder can be used to diagnose patients with recurring and unexplained arrhythmia episodes.

• #18 Atrioventricular Block – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK459147/

  Ambulatory ECG monitoring is considered a superior diagnostic tool to establish a more accurate correlation between symptoms and an AV block. It offers a higher diagnostic yield for identifying a paroxysmal AV block, thereby aiding in the accurate diagnosis of this condition. […] Implantation of a permanent pacemaker is the mainstay of treatment for patients with AV block. Asymptomatic patients with first-degree AV block, second-degree type I AV block, or 2:1 AV block at the AV node level usually do not require a pacemaker. […] Permanent pacemaker implantation must be considered in patients with symptomatic second-degree AV block, high-degree AV block, or third-degree AV block who do not have a reversible cause of the AV block. […] According to the current guidelines, a dual-chamber pacemaker is recommended over a single-chamber pacemaker.

• #19 Heart Block: Types, Causes, Symptoms, and Risk Factors

  https://www.verywellhealth.com/heart-block-8709735

  Heart block is a delay or disruption within the heart’s electrical conduction system that controls the rhythm and beats, causing the heart to beat slowly or skip beats. […] The primary test for diagnosing heart block is an electrocardiogram (ECG). An ECG is a tool for visualizing the electrical impulse traveling through the heart as it beats. […] ECG abnormalities seen with heart block include: […] If the ECG shows a heart block, a focused medical history, physical exam, and various diagnostic tests help providers determine the underlying cause. […] Some individuals with a heart block are referred to an electrophysiologist—a cardiologist with special training in understanding the heart’s electrical activity. An electrophysiologist can perform a study to help find the precise location of the block, which helps guide the treatment plan. […] Heart block is diagnosed by an electrocardiogram (ECG) and is classified into three types that range in severity: first-degree, second-degree, and third-degree heart block.

• #20 Coronary artery disease – Diagnosis and treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/coronary-artery-disease/diagnosis-treatment/drc-20350619

  To diagnose coronary artery disease, a healthcare professional examines you. You are usually asked questions about your medical history and any symptoms. If you have symptoms of coronary artery disease such as chest pain or shortness of breath, tests may be done to check your overall health. […] Tests to help diagnose or watch coronary artery disease include: […] Electrocardiogram (ECG or EKG). This quick test checks the electrical activity of the heart. It shows how the heart is beating. […] Echocardiogram. This test uses sound waves to show blood flow through the heart. […] Exercise stress test. If your symptoms usually occur during exercise, your healthcare professional may recommend this test. […] Nuclear stress test. This test shows how blood moves to the heart at rest and during activity. […] Heart CT scan. A CT scan of the heart can show calcium deposits and blockages in the heart arteries. […] Cardiac catheterization and angiogram. This test can see blockages in the heart arteries.

• #21 Heart Block in Children | UpBeat.org – powered by the Heart Rhythm Society

  https://upbeat.org/pediatrics/heart-blocks

  Heart block, also called atrioventricular block or AV block, refers to slowing or „blocking” of the electrical impulses in the heart. […] The diagnosis of heart block is based on the relationship between the P-wave, which is the signal coming from the sinus node, and the QRS complex, which is the electrical response in the ventricles. […] The diagnosis of heart block is made based on specific findings noted on your electrocardiogram (ECG). Specifically, your healthcare team will look at the relationship between the electrical signals from the top of the heart and the electrical signals in the bottom of the heart. […] After diagnosing heart block, your healthcare team may order additional testing, such as a Holter monitor to determine the frequency and severity of the heart block. Holter monitors or other long-term monitors can also be used for routine rhythm monitoring or if there are concerns about worsening heart block or symptoms. Another common test following a heart block diagnosis is an exercise stress test, which evaluates whether the heart rate can adapt to the body’s needs during activity, especially if the patients has symptoms while exercising.

• #22 Heart Blocks: A Primer — Taming the SRU

  https://www.tamingthesru.com/blog/diagnostics/ecg-heart-blocks-primer

  Recognizing a heart block on an EKG or monitor is important, but always start your evaluation with assessment of vitals, airway, breathing, circulation and clinically correlate your findings. […] Heart blocks can be a sign of underlying pathology such as MI, Lyme disease, myocarditis, structural heart disease, pulmonary embolism, autoimmune disease, electrolyte disturbances, medication side effects, Lenegres or Levs disease, increased vagal tone, or could be a normal variant. […] Distinguishing between a 2nd degree Mobitz type 1 and type 2 block can determine whether a patient needs admission and can be difficult to determine in a 2:1 block. Vagal maneuver, PR interval, and QRS length can help you distinguish the two. […] In isolation, asymptomatic patients with a 1st degree AV block or 2nd degree Mobitz type 1 block can be discharged with follow-up.

• #23 Bundle branch block – Diagnosis & treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/bundle-branch-block/diagnosis-treatment/drc-20370518

  If you have a right bundle branch block and you’re otherwise healthy, you might not need a full medical checkup. If you have a left bundle branch block, you will need a thorough medical exam. […] Tests that can be used to diagnose a bundle branch block or its causes include: […] Electrocardiogram (ECG or EKG). This quick and painless test measures the electrical activity of the heart. […] Echocardiogram. This test uses sound waves to provide detailed images of the heart and heart valves. It can show the structure and the thickness of the heart muscle. Your provider can use this test to pinpoint a condition that caused the bundle branch block. […] For bundle branch block, questions to ask your provider include: What tests do I need? […] Has a health care provider ever told you that you have a bundle branch block?

• #24 Atrioventricular block – Wikipedia

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

  Atrioventricular block (AV block) is a type of heart block that occurs when the electrical signal traveling from the atria, or the upper chambers of the heart, to ventricles, or the lower chambers of the heart, is impaired. […] An ECG is used to differentiate between the different types of AV blocks. […] It is important to diagnose AV-blocks precisely because unnecessary pacemaker placement in patients with pseudo-AV blocks can worsen symptoms and create complications. […] An electrocardiogram, or ECG, is used to differentiate between the different types of AV block. […] If the patient is symptomatic from their suspected AV block, it is important that an ECG is also obtained while having symptoms. […] Because some types of AV block can be associated with underlying structural heart disease, patients may also undergo echocardiogram to look at the heart and assess the function. […] Laboratory diagnosis for AV blocks include electrolyte, drug level and cardiac enzyme level tests.

• #25 Heart Block – BHF

  https://www.bhf.org.uk/informationsupport/conditions/arrhythmias/heart-block

  How is heart block diagnosed? […] To diagnose heart block, your doctor will do different tests, like: […] An electrocardiogram (ECG). This measures the electrical activity of your heart. The results of an ECG can show the type of heart block you have. Your doctor may also want you to wear a portable ECG monitor to get a reading of the electrical activity of your heart over a longer period of time. […] Echocardiogram. A scan of the heart similar to an ultrasound that makes a picture of your heart. […] Cardiac MRI. A type of scan that takes detailed pictures of the inside of your heart and blood vessels.

• #26 Heart block | NHS inform

  https://www.nhsinform.scot/illnesses-and-conditions/cardiovascular-disease/heart-disease/heart-block/

  Diagnosing a heart block is crucial for determining the appropriate treatment. […] Blood tests are usually recommended to check that your heart block is not the result of an infection such as Lyme disease, or high levels of certain medication. […] You may also be referred for an electrocardiogram (ECG). An ECG is a test that measures the electrical activity of your heart. It may be carried out while you are exercising (usually on a treadmill or an exercise bike) or while you are resting. […] Congenital third degree heart block may be detected during pregnancy using an ultrasound scan. The scanner can be used to measure how quickly your baby’s heart is beating. An abnormally slow heartbeat may signify a heart block. […] Acquired third degree heart block is usually diagnosed using a combination of blood tests and an ECG. In some cases, an echocardiogram may also be performed if it is thought that there is inflammation affecting the heart muscles. […] Due to the often critical nature of third degree heart block, treatment may begin before the results of all of the blood tests are known.

• #27 Atrioventricular block – Symptoms, diagnosis and treatment | BMJ Best Practice

  https://bestpractice.bmj.com/topics/en-gb/728

  Atrioventricular (AV) block can be described by degree (based on ECG appearance) or by anatomical level of block. […] The degree of AV block or anatomical level of block does not necessarily correlate with the severity of subsequent symptoms. […] The goals of therapy are to treat symptoms and to prevent syncope and sudden cardiac death due to very slow or absent ventricular rates. […] Patients with advanced AV block (usually type II second-degree, third-degree, or infranodal AV block) of irreversible cause should undergo permanent pacemaker placement. […] Key diagnostic factors include presence of risk factors, age 50-60 years, syncope, heart rate 40 bpm, and pre-syncope. […] 1st investigations to order include 12-lead ECG, serum troponin, serum potassium, serum calcium, serum pH, and serum digitalis level. […] Investigations to consider include 24-hour ambulatory monitoring or event monitoring, chest x-ray, transthoracic echocardiogram, serological testing for Lyme disease, tilt-table testing, electrophysiological study, cardiac stress testing, coronary angiography, and serum CK-MB.

• #28 Third-degree atrioventricular block – Wikipedia

  https://en.wikipedia.org/wiki/Third-degree_atrioventricular_block

  Third-degree atrioventricular block (AV block) is a medical condition in which the electrical impulse generated in the sinoatrial node (SA node) in the atrium of the heart can not propagate to the ventricles. […] Diagnosis is largely focussed on analysis of the patients 12-lead ECG. A patient with a third-degree AV block will likely have p-waves not corresponding to QRS complexes along with bradycardia. […] Early treatment of atrioventricular blockade is based on the presence and severity of symptoms and signs associated with ventricular escape rhythm. Hemodynamically unstable patients require immediate medication and in most cases temporary pacing to increase heart rate and cardiac output. […] Once the patient is hemodynamically stable, a potentially reversible cause should be evaluated and treated. If no reversible cause is identified, a permanent pacemaker is inserted.

• #29 Third degree AV block – WikEM

  https://wikem.org/wiki/Third_degree_AV_block

  Rhythm strip showing third degree AV block. Note that the P waves are not related to the QRS complexes (PP interval and QRS interval both constant), demonstrating that the atria are electrically disconnected from the ventricles. […] No conduction through the AV node, causing the atria and ventricles beat completely independently from each other. […] No atrial impulses are conducted. […] P waves normal and regular P-P intervals unrelated to slower regular R-R intervals. […] QRS narrow if block above bundle of His. […] QRS wide if block below bundle of His. […] Differentiate from AV dissociation without complete heart block.

• #30 Heart Blocks: A Primer — Taming the SRU

  https://www.tamingthesru.com/blog/diagnostics/ecg-heart-blocks-primer

  High grade 2nd degree, 2nd degree Mobitz type 2 and 3rd degree AV blocks require admission for pacemaker placement and/or evaluation. […] Treatment with Atropine is indicated in bradycardic, symptomatic and/or unstable patients with a 1st or 2nd degree Mobitz type 1 AV block. It is unlikely to be affective in high grade blocks as the block is usually below the AV node. […] In symptomatic or unstable bradycardic patients, have the transcutaneous pacer pads placed while simultaneously administering chronotropic agents such as Epinephrine; pacing is definitive treatment. […] If transcutaneous pacing and chronotropic treatment is ineffective, prepare for transvenous pacing and obtain expert consultation. […] AV Blocks – Blocks that delay or prevent atrial impulses from reaching the ventricles. A 1st degree AV block and 2nd degree type 1 Wenckebach are usually caused by impaired conduction within the AV node, while a 2nd degree Mobitz type 2 is caused by impaired conduction just below the AV node. A 3rd degree AV block is caused by a complete block of conduction within or below the AV node.

• #31 Diagnosis and Management of Fetal Autoimmune Atrioventricular Block | IJWH

  https://www.dovepress.com/diagnosis-and-management-of-fetal-autoimmune-atrioventricular-block-peer-reviewed-fulltext-article-IJWH

  Diagnosis and Management of Fetal Autoimmune Atrioventricular Block […] The American Heart Association published guidelines for monitoring pregnant women with anti-Ro/Sjgrens syndrome antigen A (SSA) or anti-La/Sjgrens syndrome antigen B (SSB) autoantibodies, which are considered to increase the risk of CAVB. […] According to the American College of Obstetricians and Gynecologists, fetal bradycardia is defined as a sustained fetal heart rate 110 beats/min, and it is caused by fetal atrioventricular (AV) block, sinus bradycardia, and blocked atrial bigeminy or trigeminy. […] The degree of AV block can be categorized as first-degree, second-degree, and third-degree (complete) AV block. […] According to the American Heart Association, pregnant women with anti-Ro/SSA or anti-La/SSB autoantibodies should be referred for fetal echocardiography monitoring from 16-18 to 28 weeks of gestation with 12-week intervals.

• #32 Complete Heart Block | Fetal Care Center

  https://www.cincinnatichildrens.org/service/f/fetal-care/conditions/heart-block

  Fetal echocardiograms are used to diagnose congenital complete heart block. Additional procedures, such as M-mode tracing and Doppler ultrasound can show the relationship between a faster heart rate in the atria and a slower heart rate in the ventricles. In fetuses with complete heart block, the rates will not be synchronized. These procedures can also reveal associated problems with the structure of the fetal heart. […] Women who know they have antibodies in response to an autoimmune disease should have fetal echocardiography at 18 and at 22 weeks gestation. If these studies are normal, obstetricians may continue to follow the fetal heart rate, particularly if the mother previously had a child with complete congenital heart block. Congenital complete heart block usually develops between 18 and 30 weeks gestation.

• #33 Diagnosis and Management of Fetal Autoimmune Atrioventricular Block | IJWH

  https://www.dovepress.com/diagnosis-and-management-of-fetal-autoimmune-atrioventricular-block-peer-reviewed-fulltext-article-IJWH

  The normal PR interval in fetuses is 0.12 ± 0.02 second, and the cut-off of 0.15 s has been widely used to diagnose first-degree AV block. […] The development of CAVB sometimes does not follow the normal disease progression and the duration of progression can sometimes be unpredictable. […] However, the PR Interval and Dexamethasone Evaluation (PRIDE) study recommended conducting intensive fetal cardiac scans for signs of cardiac damage, i.e., pericardial effusion, left ventricular enlargement or poor contraction, AV valve regurgitation or hydrops fetalis including assessing the mechanical PR interval from 16 to 24 weeks of gestation with a frequency not less than one week interval. […] Although ambulatory monitoring of the fetal heart sound in autoantibody-positive pregnancies can detect fetal arrhythmia and might improve detection of fetal CAVB, this cannot totally replace echocardiography because some early signs, such as endocardial fibroelastosis, poor ventricular function or first-degree CAVB, can be missed.

• #34 Heart Block | Children’s Hospital of Philadelphia

  https://www.chop.edu/conditions-diseases/heart-block

  Heart block occurs when there is a delay in the conduction of the electrical impulse through the heart. In most cases, heart block is caused by a problem with the A-V node. […] Diagnosis of heart block may require some or all of these tests: Electrocardiogram (ECG or EKG): a record of the electrical activity of the heart […] In other cases, heart block in children is not diagnosed until a later age, or even adulthood. […] Sometimes complete heart block is diagnosed prenatally. With fetal echocardiography, doctors may notice a difference between the rate at which the upper and the lower chambers are beating.

• #35 Myocarditis With Complete Heart Block: Challenges in Diagnosis and Treatment | Consultant360

  https://www.consultant360.com/article/myocarditis-complete-heart-block-challenges-diagnosis-and-treatment

  Children with acute myocarditis often present with dyspnea at rest, exercise intolerance, syncope, tachypnea, tachycardia, and hepatomegaly. […] Various arrhythmias, complete heart block, and tachycardia with metabolic acidosis may be present. […] ECG may show sinus, atrial, and ventricular tachycardia and, occasionally, varying degrees of heart block, including complete heart block. […] The patient was admitted to the pediatric ICU, where an ECG indicated complete heart block and the development of myocardial necrosis. […] Complete heart block secondary to myocarditis was diagnosed, and treatment with dobutamine and milrinone was started. […] Complete heart block, an often transient conduction abnormality, may be an indication for transvenous pacing. […] Sinus, atrial, and ventricular tachycardia may be seen, and occasionally, varying degrees of heart block, including complete heart block, may occur.

• #36 Heart block: MedlinePlus Medical EncyclopediaLock

  https://medlineplus.gov/ency/article/007658.htm

  Heart block is a problem in the electrical signals in the heart. […] Heart block occurs when the electrical signal is slowed down or does not reach the bottom chambers of the heart. […] There are three degrees of heart block. […] Your provider may send you to a heart doctor (cardiologist) to check for or further evaluate heart block. […] The cardiologist will also: Do an ECG test to check the electrical signals in your heart. […] If you have second- or third-degree heart block, you may need a pacemaker to help your heart beat regularly. […] The treatment for heart block depends on the type of heart block you have and the cause. […] If a medicine is causing heart block, changing medicines can fix the problem.

• #37 First Degree Heart Block • LITFL • ECG Library Diagnosis

  https://litfl.com/first-degree-heart-block-ecg-library/

  PR interval 200ms (five small squares) […] There is delay, without interruption, in conduction from atria to ventricles […] Marked first degree heart block is present if PR interval 300ms […] As an isolated finding this is a benign entity that does not cause haemodynamic instability […] No specific treatment is required.

• #38 Atrioventricular Block – Cardiovascular Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/cardiovascular-disorders/specific-cardiac-arrhythmias/atrioventricular-block

  Most patients require a pacemaker. […] AV block caused by anterior myocardial infarction usually reflects extensive myocardial necrosis involving the His-Purkinje system and requires immediate transvenous pacemaker insertion with interim external pacing as necessary. […] Most patients with isolated congenital third-degree AV block have a junctional escape rhythm that maintains a reasonable rate, but they require a permanent pacemaker before they reach middle age.

• #39 Heart Block: Types, Symptoms & Causes

  https://my.clevelandclinic.org/health/diseases/17056-heart-block

  If you need a pacemaker, your provider will talk to you about the details, the type thats best for you, and what to expect before, during and after you get your pacemaker. […] If you have a pacemaker, your cardiologist will want to check it periodically to make sure that it continues to work well. They can monitor you remotely, but youll need annual in-person appointments when your provider evaluates and adjusts your pacemaker. […] It can be unnerving to have chest pain or have trouble catching your breath. But getting a heart block diagnosis can explain why youre experiencing those symptoms. The good news is that people who need treatment can have success with medicines or pacemakers that keep their hearts in a normal rhythm.

• #40 Heart Block: Causes, Symptoms, Diagnosis, & Treatment » Cardiology Bangladesh – কার্ডিওলজি বাংলাদেশ

  https://cardiologybd.com/health-wellness/heart-block-causes-symptoms-diagnosis-treatment/

  Heart block, medically known as atrioventricular (AV) block, is a condition that disrupts the normal electrical signals that control the heartbeat. […] The diagnosis of heart block typically involves a combination of clinical evaluation and diagnostic tests. Healthcare providers may use the following methods to assess and diagnose heart block: Medical History and Physical Examination: Healthcare professionals will gather information about the patients medical history, including any symptoms, underlying health conditions, medications, and family history. A physical examination may reveal signs of heart block, such as an irregular pulse. […] An ECG is a primary tool for diagnosing heart block. It records the hearts electrical activity and can identify the specific type and degree of heart block. It may be performed at rest or during exercise to capture any dynamic changes in heart rhythm. […] Once the diagnosis is confirmed, healthcare providers will determine the type and degree of heart block and evaluate the underlying cause to guide treatment decisions.

• #41 3rd Degree Heart Block: Causes, Symptoms, Outlook

  https://www.healthline.com/health/heart-disease/3rd-degree-heart-block

  Third-degree heart block is a medical emergency and can be fatal without prompt treatment. […] The main tests that are used to diagnose third-degree heart block are: an electrocardiogram (ECG), an electrophysiology study, and heart rhythm monitoring. […] An ECG relies on electrodes placed on the skin to record the heart’s electrical activity. […] Because third-degree heart block can be intermittent, an ECG may not diagnose it. Heart rhythm monitoring can be done with a Holter monitor or a patch monitor. […] Other criteria used to diagnose third-degree heart block include: a review of symptoms, medical history, physical examination, and review of current medications. […] Treatment requires urgent pacemaker placement. […] A pacemaker is a small battery-powered device that’s implanted in the chest.

• #42 Atrioventricular Block | Treatment & Management | Point of Care

  https://www.statpearls.com/point-of-care/36720

  Ambulatory ECG monitoring is considered a superior diagnostic tool to establish a more accurate correlation between symptoms and an AV block. It offers a higher diagnostic yield for identifying a paroxysmal AV block, thereby aiding in the accurate diagnosis of this condition. […] Routine invasive evaluation is not recommended for an AV block. In cases where initial non-invasive investigations fail to provide a definitive diagnosis, patients experiencing symptoms related to bradycardia should be considered for an implantable loop recorder or an electrophysiology study. […] Implantation of a permanent pacemaker is the mainstay of treatment for patients with AV block. Asymptomatic patients with first-degree AV block, second-degree type I AV block, or 2:1 AV block at the AV node level usually do not require a pacemaker. […] Permanent pacemaker implantation must be considered in patients with symptomatic second-degree AV block, high-degree AV block, or third-degree AV block who do not have a reversible cause of the AV block.

• #43 Heart Conduction Disorders | American Heart Association

  https://www.heart.org/en/health-topics/arrhythmia/about-arrhythmia/conduction-disorders

  Heart block is a delay in the electrical signals that progress from the heart’s upper chambers (atria) to its lower chambers (ventricles). When those signals don’t transmit properly, the heart beats irregularly. […] First-degree heart block occurs when the electrical impulse moves through the heart’s AV node slower than normal. This usually results in a slower heart rate. First-degree heart block rarely causes symptoms and may not need treatment. […] Second-degree heart block occurs when only some electrical signals from the heart’s upper chambers reach the lower chambers. This can cause the heart to miss beats and beat slowly and irregularly. […] In third-degree, or complete, heart block, electrical signals can’t pass from the heart’s upper chambers to its lower chambers. Without electrical impulses from the sinus node, the ventricles will still contract and pump blood, but at a slower rate than usual. […] People with third-degree heart block require immediate medical attention. Their irregular and unreliable heartbeats heighten the risk of cardiac arrest.

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