accelerated idioventricular rhythm
Pronunciation: A-I-V-R
Also written as: AIVR — accelerated idioventricular rhythm
Ventricular escape rhythm occurring at rates of 50-120 bpm, commonly seen during reperfusion after myocardial infarction.
Full Definition
Accelerated idioventricular rhythm (AIVR) is a ventricular rhythm that occurs at rates faster than typical idioventricular escape rhythms but slower than ventricular tachycardia, typically between 50-120 beats per minute. The rhythm originates from ventricular pacemaker cells and is characterized by wide QRS complexes with atrioventricular dissociation. AIVR is most commonly observed during the reperfusion phase of acute myocardial infarction and is generally considered a benign 'reperfusion arrhythmia.' Unlike ventricular tachycardia, AIVR rarely causes hemodynamic instability and usually does not require specific treatment. The rhythm often terminates spontaneously when sinus rhythm recovers or when the underlying ischemia resolves.
Usage
Usage note: Distinguish from VT by rate criteria; often indicates reperfusion in MI setting.
In Context
- "Accelerated idioventricular rhythm was noted during primary PCI, consistent with successful reperfusion of the occluded vessel." — Cardiac catheterization report
- "The patient's AIVR resolved spontaneously without treatment as sinus rhythm returned post-thrombolysis." — CCU progress note