POLYMORPHOUS VENTRICULAR-TACHYCARDIA EARLY AFTER ACUTE MYOCARDIAL-INFARCTION

Ventricular tachyarrhythmias are a major cause of cardiac death within the early hours of an evolving acute myocardial infarction. Diverse cytochemical and metabolic alterations develop in the ischemic and periischemic zones after coronary artery occlusion and subsequent reperfusion.1,2 These alterations change rapidly over time and may cause various morphologically distinct ventricular arrhythmias in the different stages of an acute myocardial infarction.1,3 One type of malignant ventricular tachyarrhythmia that appears during an acute myocardial infarction is polymorphous ventricular tachycardia (VT).3,4 The electrophysiologic mechanism and the therapy differ from those of other forms of VT.5,6 The occurrence of polymorphous VT in the early stages of an acute myocardial infarction has been infrequently reported,4 although an incidence of 1.2 to 2% during overall hospitalization for acute myocardial infarction had been reported.4 This report describes the clinical and electrocardiographic features of patients with polymorphous VT in the early stages of an evolving acute myocardial infarction. © 1993.