while the majority of victims have severe coronary heart disease , sudden cardiac death is infrequently caused by acute myocardial infarction ( 20 % ) but is predominantly related to malignant ventricular arrhythmias ( i.e. , ventricular fibrillation or sustained ventricular tachycardia ) .
C0085612
ventricular arrhythmias
C0042510
ventricular fibrillation