Sudden cardiac death during ambulatory Holter monitoring. Report on 3 documented cases.

Three cases are presented who died suddenly while being continuously monitored on ambulatory Holter ECG. Two patients with coronary artery disease and severe left ventricular dysfunction after multiple myocardial infarctions died instantly from ventricular fibrillation; this was preceded by a rapid uniform ventricular tachycardia in one patient with normal Q-T interval and by polymorphous ventricular tachycardia in the other whose Q-T was prolonged on combined antiarrhythmic therapy with propafenone and mexiletine. The third patient died from rapidly progressive circulatory failure and acute pulmonary edema due to secondary cardiomyopathy. Despite its occurrence within 30 min after the onset of symptoms, death was not primarily arrhythmic in origin.