BACK TOTOP Browse A-ZSearchBrowse A-ZABCDEFGHIJKLMNOPQRSTUVWXYZ0-9 E-mail FormEmail ResultsName:Email address:Recipients Name:Recipients address:Message: Print-FriendlyBookmarksbookmarks-menuArrhythmiasAbnormal heart rhythms; Bradycardia; Tachycardia; FibrillationAn arrhythmia is a disorder of the heart rate (pulse) or heart rhythm. The heart can beat too fast (tachycardia), too slow (bradycardia), or irregularly.Heart rateThe pulse is the number of heartbeats per minute.ImageRead Article Now Book Mark Article An arrhythmia can be harmless, a sign of other heart problems, or an immediate danger to your health. Causes Related video goes here for no-HTML5 browsersNormally, your heart works as a pump that brings blood to the lungs and the rest of the body.To help this happen, your heart has an electrical system that makes sure it contracts (squeezes) in an orderly way.The electrical impulse that signals your heart to contract begins in an area of the heart called the sinoatrial node (also called the sinus node or SA node). This is your heart's natural pacemaker. The signal leaves the SA node and travels through the heart along a set electrical pathway. Different nerve messages signal your heart to beat slower or faster. Related video goes here for no-HTML5 browsersArrhythmias are caused by problems with the heart's electrical conduction system. Abnormal extra signals may occur. Electrical signals may be blocked or slowed. Electrical signals travel in new or different pathways through the heart. Some common causes of abnormal heartbeats are:Abnormal levels of potassium, magnesium, or other substances in the body Heart attack, or a damaged heart muscle from a past heart attack Heart disease that is present at birth (congenital) Heart failure or an enlarged heart Overactive thyroid gland No audio descriptionWith audio descriptionRelated video goes here for no-HTML5 browsersRelated video goes here for no-HTML5 browsersArrhythmias may also be caused by some substances or drugs, including:Alcohol or stimulant drugs Certain medicines Cigarette smoking (nicotine)Some of the more common abnormal heart rhythms are:Atrial fibrillation or flutter Atrial fibrillation or flutterAtrial fibrillation (AFib) and atrial flutter are common types of abnormal heart rhythms (arrhythmias) which affect the upper chambers (atria) of the...ImageRead Article Now Book Mark Article Atrioventricular nodal reentry tachycardia (AVNRT) Heart block or atrioventricular block Multifocal atrial tachycardia Multifocal atrial tachycardiaMultifocal atrial tachycardia (MAT) is a rapid heart rate. It occurs when too many signals (electrical impulses) are sent from the upper heart (atri...ImageRead Article Now Book Mark Article Paroxysmal supraventricular tachycardia Paroxysmal supraventricular tachycardiaParoxysmal supraventricular tachycardia (PSVT) is episodes of a rapid heart rate that start in a part of the heart above the ventricles. "Paroxysmal...ImageRead Article Now Book Mark Article Sick sinus syndrome Sick sinus syndromeNormally, the heartbeat starts in an area in the top chambers of the heart (atria). This area is the heart's pacemaker. It is called the sinoatrial...ImageRead Article Now Book Mark Article Ventricular fibrillation or ventricular tachycardia Ventricular fibrillationVentricular fibrillation (VF) is a severely abnormal heart rhythm (arrhythmia) that is life threatening.ImageRead Article Now Book Mark Article Wolff-Parkinson-White syndromeWolff-Parkinson-White syndromeWolff-Parkinson-White (WPW) syndrome is a condition in which there is an extra electrical pathway in the heart that leads to periods of rapid heart r...ImageRead Article Now Book Mark Article Symptoms When you have an arrhythmia, your heartbeat may be:Too slow (bradycardia) Too quick (tachycardia) Irregular, uneven, possibly with extra or skipped beats An arrhythmia may be present all of the time or it may come and go. You may or may not feel symptoms when the arrhythmia is present. Or, you may only notice symptoms when you are more active.Symptoms can be very mild, or they may be severe or even life threatening.Common symptoms that may occur when the arrhythmia is present could include:Chest pain Chest painChest pain is discomfort or pain that you feel anywhere along the front of your body between your neck and upper abdomen.ImageRead Article Now Book Mark Article Fainting FaintingFainting is a brief loss of consciousness due to a drop in blood flow to the brain. The episode most often lasts less than a couple of minutes and y...Read Article Now Book Mark Article Lightheadedness, dizziness LightheadednessFainting is a brief loss of consciousness due to a drop in blood flow to the brain. The episode most often lasts less than a couple of minutes and y...Read Article Now Book Mark Article DizzinessDizziness is a term that is often used to describe 2 different symptoms: lightheadedness and vertigo. Lightheadedness is a feeling that you might fai...ImageRead Article Now Book Mark Article Paleness PalenessPaleness is an abnormal loss of color from normal skin or mucous membranes.ImageRead Article Now Book Mark Article Palpitations (feeling your heart beat fast or irregularly) Shortness of breath Shortness of breathBreathing difficulty may involve:Difficult breathing Uncomfortable breathingFeeling like you are not getting enough airImageRead Article Now Book Mark Article Sweating Exams and Tests The health care provider will listen to your heart with a stethoscope and feel your pulse. Your blood pressure may be low or normal or even high as a result of being uncomfortable.An electrocardiogram (ECG) will be the first test done.ECGAn electrocardiogram (ECG) is a test that records the electrical activity of the heart.ImageRead Article Now Book Mark Article Related video goes here for no-HTML5 browsersHeart monitoring devices are often used to identify the rhythm problem, such as a: Holter monitor (where you wear a device that records and stores your heart rhythm for 24 or more hours) Holter monitorA Holter monitor is a machine that continuously records the heart's rhythms. The monitor is worn for 24 to 48 hours during normal activity.ImageRead Article Now Book Mark Article Event monitor or loop recorder (worn for 2 weeks or longer, where you record your heart rhythm when you feel an abnormal rhythm) Other long-term monitoring options Related video goes here for no-HTML5 browsersAn echocardiogram is sometimes ordered to examine the size or structure of your heart.EchocardiogramAn echocardiogram is a test that uses sound waves to create pictures of the heart. The picture and information it produces is more detailed than a s...ImageRead Article Now Book Mark Article In selected cases, coronary angiography may be performed to see how blood flows through the arteries in your heart.Coronary angiographyCoronary angiography is a procedure that uses a special dye (contrast material) and x-rays to see how blood flows through the arteries in your heart....ImageRead Article Now Book Mark Article A special test, called an electrophysiology study (EPS), is sometimes done to take a closer look at the heart's electrical system.Electrophysiology studyIntracardiac electrophysiology study (EPS) is a test to look at how well the heart's electrical signals are working. It is used to evaluate abnormal...ImageRead Article Now Book Mark Article Related video goes here for no-HTML5 browsers Treatment When an arrhythmia is serious, you may need urgent treatment to restore a normal rhythm. This may include:Electrical therapy (defibrillation or cardioversion) Implanting a short-term heart pacemaker Medicines given through a vein or by mouth Sometimes, better treatment for your angina or heart failure will lower your chance of having an arrhythmia.Medicines called anti-arrhythmic drugs may be used: To prevent an arrhythmia from happening again To keep your heart rate from becoming too fast or too slow Some of these medicines can have side effects. Take them as prescribed by your provider. Do not stop taking the medicine or change the dose without first talking to your provider.Other treatments to prevent or treat abnormal heart rhythms include:Cardiac ablation, used to target areas in your heart that may be causing your heart rhythm problems Cardiac ablationCardiac ablation is a procedure that is used to scar small areas in your heart that may be involved in your heart rhythm problems. This can prevent ...ImageRead Article Now Book Mark Article An implantable cardioverter defibrillator, placed in people who are at high risk of sudden cardiac death Implantable cardioverter defibrillatorAn implantable cardioverter-defibrillator (ICD) is a device that detects a life-threatening, rapid heartbeat. This abnormal heartbeat is called an a...ImageRead Article Now Book Mark Article Permanent pacemaker, a device that senses when your heart is beating too slowly. It sends a signal to your heart that makes your heart beat at the correct pace. PacemakerA pacemaker is a small, battery-operated device. This device senses when your heart is beating too slowly. It sends a signal to your heart that mak...ImageRead Article Now Book Mark Article Outlook (Prognosis) The outcome depends on several factors:The kind of arrhythmia you have. Whether you have coronary artery disease, heart failure, or valvular heart disease.Coronary artery diseaseCoronary heart disease is a narrowing of the blood vessels that supply blood and oxygen to the heart. Coronary heart disease (CHD) is also called co...ImageRead Article Now Book Mark Article Heart failureHeart failure is a condition in which the heart is no longer able to pump oxygen-rich blood to the rest of the body efficiently. This causes symptom...ImageRead Article Now Book Mark Article When to Contact a Medical Professional Contact your provider if:You develop any of the symptoms of a possible arrhythmia. You have been diagnosed with an arrhythmia and your symptoms worsen or do not improve with treatment. Prevention Taking steps to prevent coronary artery disease may reduce your chance of developing an arrhythmia.Prevent coronary artery diseaseCoronary heart disease (CHD) is a narrowing of the blood vessels that supply blood and oxygen to the heart. CHD is also called coronary artery disea...Read Article Now Book Mark Article Open ReferencesReferencesAl-Khatib SM, Stevenson WG, Ackerman MJ, et al. 2017 AHA/ACC/HRS guideline for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: Executive summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Heart Rhythm. 2018;15(10):e190-e252. PMID: 29097320 pubmed.ncbi.nlm.nih.gov/29097320/.Nattel S, Tomaselli GF. Mechanisms of cardiac arrhythmias. In: Libby P, Bonow RO, Mann DL, Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 62.Olgin JE. Approach to the patient with suspected arrhythmia. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 49.Tracy CM, Epstein AE, Darbar D, et al. 2012 ACCF/AHA/HRS focused update of the 2008 guidelines for device-based therapy of cardiac rhythm abnormalities: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2012;60(14):1297-1313. PMID: 22975230 pubmed.ncbi.nlm.nih.gov/22975230/.AllVideoImagesTogHeart - section through the middle - illustration The interior of the heart is composed of valves, chambers, and associated vessels.Heart - section through the middleillustrationHeart - front view - illustration The external structures of the heart include the ventricles, atria, arteries and veins. Arteries carry blood away from the heart while veins carry blood into the heart. The vessels colored blue indicate the transport of blood with relatively low content of oxygen and high content of carbon dioxide. The vessels colored red indicate the transport of blood with relatively high content of oxygen and low content of carbon dioxide.Heart - front viewillustrationNormal heart rhythm - illustration An electrocardiogram (ECG) test measures the electrical activity of the heart. A normal resting heart rate is 60 to 100 beats per minute.Normal heart rhythmillustrationBradycardia - illustration Bradycardia heart rhythms are characterized by a slowness of the heartbeat, usually at a rate under 60 beats per minute (normal resting rate is 60 to 100 beats per minute).BradycardiaillustrationVentricular tachycardia - illustration Ventricular tachycardia is a rapid resting heart rate initiated within the ventricles, typically at 160 to 240 beats per minute (normal resting rate is 60 to 100 beats per minute).Ventricular tachycardiaillustrationAtrioventricular block - ECG tracing - illustration This picture shows an ECG (electrocardiogram, EKG) of a person with an abnormal rhythm (arrhythmia) called an atrioventricular (AV) block. P waves show that the top of the heart received electrical activity. Each P wave is usually followed by the tall (QRS) waves. QRS waves reflect the electrical activity that causes the heart to contract. When a P wave is present and not followed by a QRS wave (and heart contraction), there is an atrioventricular block, and a very slow pulse (bradycardia).Atrioventricular block - ECG tracingillustrationConduction system of the heart - illustration The intrinsic conduction system sets the basic rhythm of the beating heart by generating impulses which stimulate the heart to contract.Conduction system of the heartillustrationHeart - section through the middle - illustration The interior of the heart is composed of valves, chambers, and associated vessels.Heart - section through the middleillustrationHeart - front view - illustration The external structures of the heart include the ventricles, atria, arteries and veins. Arteries carry blood away from the heart while veins carry blood into the heart. The vessels colored blue indicate the transport of blood with relatively low content of oxygen and high content of carbon dioxide. The vessels colored red indicate the transport of blood with relatively high content of oxygen and low content of carbon dioxide.Heart - front viewillustrationNormal heart rhythm - illustration An electrocardiogram (ECG) test measures the electrical activity of the heart. A normal resting heart rate is 60 to 100 beats per minute.Normal heart rhythmillustrationBradycardia - illustration Bradycardia heart rhythms are characterized by a slowness of the heartbeat, usually at a rate under 60 beats per minute (normal resting rate is 60 to 100 beats per minute).BradycardiaillustrationVentricular tachycardia - illustration Ventricular tachycardia is a rapid resting heart rate initiated within the ventricles, typically at 160 to 240 beats per minute (normal resting rate is 60 to 100 beats per minute).Ventricular tachycardiaillustrationAtrioventricular block - ECG tracing - illustration This picture shows an ECG (electrocardiogram, EKG) of a person with an abnormal rhythm (arrhythmia) called an atrioventricular (AV) block. P waves show that the top of the heart received electrical activity. Each P wave is usually followed by the tall (QRS) waves. QRS waves reflect the electrical activity that causes the heart to contract. When a P wave is present and not followed by a QRS wave (and heart contraction), there is an atrioventricular block, and a very slow pulse (bradycardia).Atrioventricular block - ECG tracingillustrationConduction system of the heart - illustration The intrinsic conduction system sets the basic rhythm of the beating heart by generating impulses which stimulate the heart to contract.Conduction system of the heartillustrationRelated Information Pulse(Medical Test)Angina(Condition)Heart attack(Condition)Heart failure(Condition)Stroke(Condition)Atrial myxoma(Condition)Cardiac ablation procedures (Surgery)Heart pacemaker(Surgery)Atrial fibrillation - discharge (Discharge)Taking warfarin (Coumadin, Jantoven) - what to ask your doctor(Doctor Questions)Heart pacemaker - discharge(Discharge)Coronary artery disease - InDepth(In-Depth)Heart attack and acute coronary syndrome - InDepth(In-Depth)Heart failure - InDepth(In-Depth) Review Date: 5/27/2024 Reviewed By: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited. © 1997- All rights reserved. A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.Content is best viewed in IE9 or above, Firefox and Google Chrome browser.
ArrhythmiasAbnormal heart rhythms; Bradycardia; Tachycardia; FibrillationAn arrhythmia is a disorder of the heart rate (pulse) or heart rhythm. The heart can beat too fast (tachycardia), too slow (bradycardia), or irregularly.Heart rateThe pulse is the number of heartbeats per minute.ImageRead Article Now Book Mark Article An arrhythmia can be harmless, a sign of other heart problems, or an immediate danger to your health. Causes Related video goes here for no-HTML5 browsersNormally, your heart works as a pump that brings blood to the lungs and the rest of the body.To help this happen, your heart has an electrical system that makes sure it contracts (squeezes) in an orderly way.The electrical impulse that signals your heart to contract begins in an area of the heart called the sinoatrial node (also called the sinus node or SA node). This is your heart's natural pacemaker. The signal leaves the SA node and travels through the heart along a set electrical pathway. Different nerve messages signal your heart to beat slower or faster. Related video goes here for no-HTML5 browsersArrhythmias are caused by problems with the heart's electrical conduction system. Abnormal extra signals may occur. Electrical signals may be blocked or slowed. Electrical signals travel in new or different pathways through the heart. Some common causes of abnormal heartbeats are:Abnormal levels of potassium, magnesium, or other substances in the body Heart attack, or a damaged heart muscle from a past heart attack Heart disease that is present at birth (congenital) Heart failure or an enlarged heart Overactive thyroid gland No audio descriptionWith audio descriptionRelated video goes here for no-HTML5 browsersRelated video goes here for no-HTML5 browsersArrhythmias may also be caused by some substances or drugs, including:Alcohol or stimulant drugs Certain medicines Cigarette smoking (nicotine)Some of the more common abnormal heart rhythms are:Atrial fibrillation or flutter Atrial fibrillation or flutterAtrial fibrillation (AFib) and atrial flutter are common types of abnormal heart rhythms (arrhythmias) which affect the upper chambers (atria) of the...ImageRead Article Now Book Mark Article Atrioventricular nodal reentry tachycardia (AVNRT) Heart block or atrioventricular block Multifocal atrial tachycardia Multifocal atrial tachycardiaMultifocal atrial tachycardia (MAT) is a rapid heart rate. It occurs when too many signals (electrical impulses) are sent from the upper heart (atri...ImageRead Article Now Book Mark Article Paroxysmal supraventricular tachycardia Paroxysmal supraventricular tachycardiaParoxysmal supraventricular tachycardia (PSVT) is episodes of a rapid heart rate that start in a part of the heart above the ventricles. "Paroxysmal...ImageRead Article Now Book Mark Article Sick sinus syndrome Sick sinus syndromeNormally, the heartbeat starts in an area in the top chambers of the heart (atria). This area is the heart's pacemaker. It is called the sinoatrial...ImageRead Article Now Book Mark Article Ventricular fibrillation or ventricular tachycardia Ventricular fibrillationVentricular fibrillation (VF) is a severely abnormal heart rhythm (arrhythmia) that is life threatening.ImageRead Article Now Book Mark Article Wolff-Parkinson-White syndromeWolff-Parkinson-White syndromeWolff-Parkinson-White (WPW) syndrome is a condition in which there is an extra electrical pathway in the heart that leads to periods of rapid heart r...ImageRead Article Now Book Mark Article Symptoms When you have an arrhythmia, your heartbeat may be:Too slow (bradycardia) Too quick (tachycardia) Irregular, uneven, possibly with extra or skipped beats An arrhythmia may be present all of the time or it may come and go. You may or may not feel symptoms when the arrhythmia is present. Or, you may only notice symptoms when you are more active.Symptoms can be very mild, or they may be severe or even life threatening.Common symptoms that may occur when the arrhythmia is present could include:Chest pain Chest painChest pain is discomfort or pain that you feel anywhere along the front of your body between your neck and upper abdomen.ImageRead Article Now Book Mark Article Fainting FaintingFainting is a brief loss of consciousness due to a drop in blood flow to the brain. The episode most often lasts less than a couple of minutes and y...Read Article Now Book Mark Article Lightheadedness, dizziness LightheadednessFainting is a brief loss of consciousness due to a drop in blood flow to the brain. The episode most often lasts less than a couple of minutes and y...Read Article Now Book Mark Article DizzinessDizziness is a term that is often used to describe 2 different symptoms: lightheadedness and vertigo. Lightheadedness is a feeling that you might fai...ImageRead Article Now Book Mark Article Paleness PalenessPaleness is an abnormal loss of color from normal skin or mucous membranes.ImageRead Article Now Book Mark Article Palpitations (feeling your heart beat fast or irregularly) Shortness of breath Shortness of breathBreathing difficulty may involve:Difficult breathing Uncomfortable breathingFeeling like you are not getting enough airImageRead Article Now Book Mark Article Sweating Exams and Tests The health care provider will listen to your heart with a stethoscope and feel your pulse. Your blood pressure may be low or normal or even high as a result of being uncomfortable.An electrocardiogram (ECG) will be the first test done.ECGAn electrocardiogram (ECG) is a test that records the electrical activity of the heart.ImageRead Article Now Book Mark Article Related video goes here for no-HTML5 browsersHeart monitoring devices are often used to identify the rhythm problem, such as a: Holter monitor (where you wear a device that records and stores your heart rhythm for 24 or more hours) Holter monitorA Holter monitor is a machine that continuously records the heart's rhythms. The monitor is worn for 24 to 48 hours during normal activity.ImageRead Article Now Book Mark Article Event monitor or loop recorder (worn for 2 weeks or longer, where you record your heart rhythm when you feel an abnormal rhythm) Other long-term monitoring options Related video goes here for no-HTML5 browsersAn echocardiogram is sometimes ordered to examine the size or structure of your heart.EchocardiogramAn echocardiogram is a test that uses sound waves to create pictures of the heart. The picture and information it produces is more detailed than a s...ImageRead Article Now Book Mark Article In selected cases, coronary angiography may be performed to see how blood flows through the arteries in your heart.Coronary angiographyCoronary angiography is a procedure that uses a special dye (contrast material) and x-rays to see how blood flows through the arteries in your heart....ImageRead Article Now Book Mark Article A special test, called an electrophysiology study (EPS), is sometimes done to take a closer look at the heart's electrical system.Electrophysiology studyIntracardiac electrophysiology study (EPS) is a test to look at how well the heart's electrical signals are working. It is used to evaluate abnormal...ImageRead Article Now Book Mark Article Related video goes here for no-HTML5 browsers Treatment When an arrhythmia is serious, you may need urgent treatment to restore a normal rhythm. This may include:Electrical therapy (defibrillation or cardioversion) Implanting a short-term heart pacemaker Medicines given through a vein or by mouth Sometimes, better treatment for your angina or heart failure will lower your chance of having an arrhythmia.Medicines called anti-arrhythmic drugs may be used: To prevent an arrhythmia from happening again To keep your heart rate from becoming too fast or too slow Some of these medicines can have side effects. Take them as prescribed by your provider. Do not stop taking the medicine or change the dose without first talking to your provider.Other treatments to prevent or treat abnormal heart rhythms include:Cardiac ablation, used to target areas in your heart that may be causing your heart rhythm problems Cardiac ablationCardiac ablation is a procedure that is used to scar small areas in your heart that may be involved in your heart rhythm problems. This can prevent ...ImageRead Article Now Book Mark Article An implantable cardioverter defibrillator, placed in people who are at high risk of sudden cardiac death Implantable cardioverter defibrillatorAn implantable cardioverter-defibrillator (ICD) is a device that detects a life-threatening, rapid heartbeat. This abnormal heartbeat is called an a...ImageRead Article Now Book Mark Article Permanent pacemaker, a device that senses when your heart is beating too slowly. It sends a signal to your heart that makes your heart beat at the correct pace. PacemakerA pacemaker is a small, battery-operated device. This device senses when your heart is beating too slowly. It sends a signal to your heart that mak...ImageRead Article Now Book Mark Article Outlook (Prognosis) The outcome depends on several factors:The kind of arrhythmia you have. Whether you have coronary artery disease, heart failure, or valvular heart disease.Coronary artery diseaseCoronary heart disease is a narrowing of the blood vessels that supply blood and oxygen to the heart. Coronary heart disease (CHD) is also called co...ImageRead Article Now Book Mark Article Heart failureHeart failure is a condition in which the heart is no longer able to pump oxygen-rich blood to the rest of the body efficiently. This causes symptom...ImageRead Article Now Book Mark Article When to Contact a Medical Professional Contact your provider if:You develop any of the symptoms of a possible arrhythmia. You have been diagnosed with an arrhythmia and your symptoms worsen or do not improve with treatment. Prevention Taking steps to prevent coronary artery disease may reduce your chance of developing an arrhythmia.Prevent coronary artery diseaseCoronary heart disease (CHD) is a narrowing of the blood vessels that supply blood and oxygen to the heart. CHD is also called coronary artery disea...Read Article Now Book Mark Article Open ReferencesReferencesAl-Khatib SM, Stevenson WG, Ackerman MJ, et al. 2017 AHA/ACC/HRS guideline for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: Executive summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Heart Rhythm. 2018;15(10):e190-e252. PMID: 29097320 pubmed.ncbi.nlm.nih.gov/29097320/.Nattel S, Tomaselli GF. Mechanisms of cardiac arrhythmias. In: Libby P, Bonow RO, Mann DL, Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 62.Olgin JE. Approach to the patient with suspected arrhythmia. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 49.Tracy CM, Epstein AE, Darbar D, et al. 2012 ACCF/AHA/HRS focused update of the 2008 guidelines for device-based therapy of cardiac rhythm abnormalities: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2012;60(14):1297-1313. PMID: 22975230 pubmed.ncbi.nlm.nih.gov/22975230/.
