Broad classification of<unk> s according to region of heart required to sustain the rhythm<unk>  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).<unk> s are also classified by site of origin: Atrial<unk>  *Sinus bradycardia *Sinus<unk>  *Sinus tachycardia *Premature atrial contractions (PACs) *Wandering atrial pacemaker *Atrial tachycardia *Multifocal atrial tachycardia *Supraventricular tachycardia (SVT) *Atrial flutter *Atrial fibrillation (Afib) *AV nodal reentrant tachycardia Junctional<unk>  *AV nodal reentrant tachycardia *Junctional rhythm *Junctional tachycardia *Premature junctional contraction Ventricular<unk> === *Premature ventricular contractions (PVCs), sometimes called ventricular extra beats (VEBs) *Premature ventricular beats occurring after every normal beat are termed ventricular bigeminy *PVCs that occur at intervals of 2 normal beats to 1 PVC, or 1 normal beat to 2 PVCs, are termed "PVCs in trigeminy" *Groups of three premature ventricular beats are called triplets and are considered a brief run of non-sustained ventricular tachycardia (NSVT); if the grouping lasts for more than 30 seconds, it is considered sustained ventricular tachycardia (VT). *Accelerated idioventricular rhythm *Monomorphic ventricular tachycardia *Polymorphic ventricular tachycardia *Ventricular fibrillation *Torsades de pointes *Arrhythmogenic right ventricular dysplasia *Re-entry ventricular<unk>  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-degree heart block, which manifests as PR prolongation *Second-degree heart block *Type 1 Second degree heart block, also known as Mobitz I or Wenckebach *Type 2 Second degree heart block, also known as Mobitz II *Third-degree heart block, also known as complete heart block. First, second, and third-degree blocks 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<unk>  death syndrome Sudden<unk>  death syndrome (SADS), is a term used as part of sudden unexpected death syndrome to describe sudden death because of cardiac arrest occasioned by an<unk>  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 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. 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. Fetal<unk> <unk> s may also occur in the fetus. 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<unk> . These are mainly the result of premature atrial contractions, usually give no symptoms, and have little consequence. However, around one percent of these will be the result of significant structural damage to the heart.
Arrhythmia
Drowning
Proarrhythmia
Atrial fibrillation
Hypsarrhythmia
Reflex syncope  Reflex syncope  1
Cardiovascular drift
Myocardial infarction