atrioventricular dissociation
Also written as: AV dissociation — atrioventricular dissociation
ECG finding where atrial and ventricular rhythms are independent, often indicating ventricular tachycardia.
Full Definition
An electrocardiographic phenomenon where the atria and ventricles beat independently without synchronized conduction through the AV node. This finding is pathognomonic for ventricular tachycardia when present in wide complex tachycardia, as it indicates the ventricular rhythm is originating below the AV junction. AV dissociation can be identified by recognizing P waves that occur at a different rate than the QRS complexes and occasionally 'march through' the ventricular rhythm. This finding significantly aids in differentiating VT from supraventricular tachycardia with aberrancy.
Usage
Usage note: May be abbreviated as 'AV dissociation' but should be spelled out in formal reports.
In Context
- "The ECG demonstrated clear atrioventricular dissociation, confirming the diagnosis of ventricular tachycardia." — Cardiology interpretation
- "Absence of atrioventricular dissociation suggested supraventricular tachycardia with aberrancy." — Emergency physician documentation