twelve of 15 patients ( 80 % ) experienced dysrhythmia prior to the acme of st-segment elevation ( occlusive dysrhythmia ) , and those of tachyarrhythmia type were characterized by the presence of ventricular premature beats initially isolated , increasing in frequency , and preceding the more malignant forms of dysrhythmias , such as ventricular tachycardia or ventricular fibrillation .
C0080203
tachyarrhythmia
C0003811
dysrhythmias