Other namesCardiac arrhythmia, cardiac dysrhythmia, irregular heartbeat, heart arrhythmia
Ventricular fibrillation.png
Ventricular fibrillation (VF) showing disorganized electrical activity producing a spiked tracing on an electrocardiogram (ECG)
SymptomsPalpitations, lightheadedness, passing out, shortness of breath, chest pain[1]
ComplicationsStroke, heart failure[2][3]
Usual onsetOlder age[4]
TypesExtra beats, supraventricular tachycardias, ventricular arrhythmias, bradyarrhythmias[3]
CausesProblems with the electrical conduction system of the heart[2]
Diagnostic methodElectrocardiogram, Holter monitor[5]
TreatmentMedications, medical procedures (pacemaker), surgery[6]

Arrhythmia, also known as cardiac arrhythmia or heart arrhythmia, is a group of conditions in which the heartbeat is irregular, too fast, or too slow.[2] The heart rate that is too fast – above 100 beats per minute in adults – is called tachycardia, and a heart rate that is too slow – below 60 beats per minute – is called bradycardia.[2] Some types of arrhythmias have no symptoms.[1] Symptoms when present may include palpitations or feeling a pause between heartbeats.[1] In more serious cases, there may be lightheadedness, passing out, shortness of breath or chest pain.[1] While most types of arrhythmia are not serious, some predispose a person to complications such as stroke or heart failure.[2][3] Others may result in sudden death.[3]

There are four main groups of arrhythmia: extra beats, supraventricular tachycardias, ventricular arrhythmias and bradyarrhythmias.[3] Extra beats include premature atrial contractions, premature ventricular contractions and premature junctional contractions.[3] Supraventricular tachycardias include atrial fibrillation, atrial flutter and paroxysmal supraventricular tachycardia.[3] Ventricular arrhythmias include ventricular fibrillation and ventricular tachycardia.[3][7] Arrhythmias are due to problems with the electrical conduction system of the heart.[2] Arrhythmias may also occur in children, however, the normal range for the heart rate is different and depends on age.[3] A number of tests can help with diagnosis including an electrocardiogram (ECG) and Holter monitor.[5]

Most arrhythmias can be effectively treated.[2] Treatments may include medications, medical procedures such as inserting a pacemaker and surgery.[6] Medications for a fast heart rate may include beta blockers or agents that attempt to restore a normal heart rhythm such as procainamide.[6] This latter group may have more significant side effects, especially if taken for a long period of time.[6] Pacemakers are often used for slow heart rates.[6] Those with an irregular heartbeat are often treated with blood thinners to reduce the risk of complications.[6] Those who have severe symptoms from an arrhythmia may receive urgent treatment with a controlled electric shock in the form of cardioversion or defibrillation.[6]

Arrhythmia affects millions of people.[4] In Europe and North America, as of 2014, atrial fibrillation affects about 2% to 3% of the population.[8] Atrial fibrillation and atrial flutter resulted in 112,000 deaths in 2013, up from 29,000 in 1990.[9] Sudden cardiac death is the cause of about half of deaths due to cardiovascular disease and about 15% of all deaths globally.[10] About 80% of sudden cardiac death is the result of ventricular arrhythmias.[10] Arrhythmias may occur at any age but are more common among older people.[4]


Broad classification of arrhythmias according to region of heart required to sustain the rhythm

Arrhythmia may be classified by rate (tachycardia, bradycardia), mechanism (automaticity, re-entry, triggered) or duration (isolated premature beats; couplets; runs, that is 3 or more beats; non-sustained= less than 30 seconds or sustained= over 30 seconds).

It is also appropriate to classify by site of origin:

Atrial arrhythmia

Junctional arrhythmia

Ventricular arrhythmia

Heart blocks

These are also known as AV blocks, because the vast majority of them arise from pathology at the atrioventricular node. They are the most common causes of bradycardia:

First, second and third degree block also can occur at the level of the sinoatrial junction. This is referred to as sinoatrial block typically manifesting with various degrees and patterns of sinus bradycardia.

Sudden arrhythmic death syndrome

Sudden arrhythmic death syndrome (SADS), is a term used as part of sudden unexpected death syndrome to describe sudden death due to cardiac arrest brought on by an arrhythmia in the presence or absence of any structural heart disease on autopsy. The most common cause of sudden death in the US is coronary artery disease specifically because of poor oxygenation of the heart muscle, that is myocardial ischemia or a heart attack [11] Approximately 180,000 to 250,000 people die suddenly of this cause every year in the US. SADS may occur from other causes. There are many inherited conditions and heart diseases that can affect young people which can subsequently cause sudden death without advance symptoms.[12]

Causes of SADS in young people include viral myocarditis, long QT syndrome, Brugada syndrome, Catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy and arrhythmogenic right ventricular dysplasia.[13][14]

Fetal arrhythmia

Arrhythmias can also be found in the fetus.[15] The normal heart rate of the fetus is between 110 and 160 beats per minute. Any rhythm beyond these limits is abnormal, and classed as a fetal arrhythmia. These are mainly the result of premature atrial contractions, usually give no symptoms, and have little consequence. However around one per cent of these will be the result of significant structural damage to the heart.[15]

Other Languages
беларуская: Арытмія
беларуская (тарашкевіца)‎: Арытмія
български: Аритмия
català: Arrítmia
dansk: Arytmi
Esperanto: Kora misritmo
euskara: Arritmia
한국어: 부정맥
հայերեն: Առիթմիա
hrvatski: Aritmija
Bahasa Indonesia: Aritmia
italiano: Aritmia
עברית: הפרעת קצב
Kapampangan: Cardiac arrhythmia
latviešu: Sirds aritmija
lietuvių: Aritmija
മലയാളം: അതാളത
Bahasa Melayu: Disritmia jantung
Nederlands: Hartritmestoornis
日本語: 不整脈
norsk: Arytmi
norsk nynorsk: Hjartearytmi
oʻzbekcha/ўзбекча: Aritmiya
Plattdüütsch: Hartrhythmusstören
português: Arritmia cardíaca
sicilianu: Aritmia
Simple English: Arrhythmia
slovenčina: Arytmia
slovenščina: Srčna aritmija
српски / srpski: Lupanje srca
srpskohrvatski / српскохрватски: Aritmija
svenska: Arytmi
Türkçe: Aritmi
українська: Аритмії серця
اردو: بے آہنگی
Tiếng Việt: Rối loạn nhịp tim
粵語: 心律不正
中文: 心律不整