View source for Accelerated idioventricular rhythm

==Background==
*Results when rate of an ectopic ventricular pacemaker exceeds sinus node
*Usually benign,self limiting
*Terminology
**Idioventricular rhythm: 20-40 bpm
**Accelerated idoventricular rhythm: 40-120 bpm
**Ventricular tachycardia: >120 bpm

===Causes===
*Reperfusion phase of [[acute myocardial infarction]] (most common cause)
*Beta-sympathomimetics (isoprenaline or adrenaline)
*Drug toxicity, especially [[digoxin]], [[cocaine]] and volatile anaesthetics such as desflurane
*[[Electrolyte abnormalities]]
*[[Cardiomyopathy]]
*[[congenital heart disease]]
*[[myocarditis]]
*Return of spontaneous circulation ([[ROSC]]) following [[cardiac arrest]]
*Athletic heart

==Clinical Features==
*Asymptomatic or [[palpitations]]

==Differential Diagnosis==
{{Tachycardia (wide) DDX}}
{{Palpitations DDX}}

==Evaluation==
[[File:AIVR from the LV.png|thumb|Accelerated idioventricular rhythm (AIVR) at a rate of 55/min presumably originating from the left ventricle (LV). Note the typical QRS morphology in lead V1 characteristic of ventricular ectopy from the LV. Monophasic R-wave with smooth upstroke and notching on the downstroke (i.e., the so-called taller left peak or "rabbit-ear".)]]
===[[ECG]] features===
*Regular rhythm
*Rate 50-110 bpm
*Three or more ventricular complexes
*QRS complexes >120ms
*Fusion and capture beats

==Management==
*AIVR is a benign rhythm in most settings and does not usually require treatment
*Self limiting and resolves when sinus rate exceeds that of the ventricular foci
*[[Antiarrhythmics]] may cause precipitous haemodynamic deterioration and should be '''avoided'''
*Treat the underlying cause: e.g. correct electrolytes, restore myocardial perfusion
*Patients with low-cardiac-output states (e.g. severe biventricular failure) may benefit from restoration of AV synchrony to restore atrial kick – in this case [[atropine]] may be trialled to increase sinus rate and AV conduction

==Disposition==
*Normally outpatient

==See Also==
*[[ECG]]

==External Links==
*[http://lifeinthefastlane.com/ecg-library/aivr/  LITFL - Accelerated Idioventricular Rhythm (AVIR)]

==References==
<references/>

[[Category:Cardiology]]