ventricular arrhythmia

ventricular arrhythmia An abnormal, rapid heart rhythm (arrhythmia) that originates in the lower chambers of the heart (ventricles). Ventricular arrhythmias include ventricular tachycardia and ventricular fibrillation. Both are lifethreatening arrhythmias that are commonly associated with heart attacks and scarring of the heart muscle from previous heart attacks.