Sudden death during ambulatory monitoring. Clinical and electrocardiographic correlations. Report of a case.

Abstract

A man with known coronary heart disease underwent treadmill exercise testing to determine his functional capacity. The test was negative for ischemia. Ventricular ectopic activity was noted at rest and in the recovery period. On the same day, while viewing a sporting event at home, the patient died suddenly. An ambulatory electrocardiographic recording documented ventricular fibrillations as the terminal mechanism. Ventricular ectopic activity and heart rate increased in the two hours prior to death, and ischemic ST-segment depression was noted at the time of the terminal arrhythmia. It is postulated that myocardial ischemia and catecholamine response lowered the threshold to ventricular fibrillation, thus facilitating the emergence of the fatal arrhythmia.

Clinical Applications of Ambulatory Electrocardiography

“…Sudden death occurring during ambula tory electrocardiography has been reported by several groups [96][97][98][99][100], with potentially fatal arrhythmias often, but not invariably, associated with complex or early-cycle ven tricular cctopy in patients with ischemic or myopathic hearts [96. 98, 100], Other in stances of arrhythmic death have been asso ciated with late-cycle VPCs, particularly in patients with prolonged QT intervals [96,99,100], As classified by Hinkle and Thaler [101], arrhythmic death without prior circulatory collapse occurs commonly as a terminal event when heart disease is the primary cause of the final illness ( fig.…”

Sudden Death Precipitated by Psychological Stress

“…As reviewed by Lown and Verrier (1 31, increased adrenergic activity induced by electrical stimulation of hypothalamic centers or left stellate ganglia, catecholamine infusions and emotional stress tests have been shown to predispose for VF in normal as well as ischemic animal hearts. That psychological factors in man may play a role in sudden death is exemplified in reports published by Gradman et al (6) and Lown et al (14). As regards our patient, we can only Acta Med &and 212 speculate about whether the arrhythmia was a pure effect of catecholamine stimulation or developed in combination with a tachycardia-induced ischemia due to extensive coronary arteriosclerosis.…”

Use of Programmed Stimulation in Identifying Patients at High Risk for Sudden Cardiac Death

“…Among the more seriously ill, annual mortality is 30-65%. at least half of which is the result of sudden arrhythmic death [11,12,18,[39][40][41], Ambulatory monitors worn by patients at the time of sudden death indi cate that most patients develop rapid VT which degenerates to VF [42][43][44][45][46], Use of noninvasive tests to identify patients at in creased risk of sudden death has met only limited success. For this reason, investiga tions are underway to examine the utility of electrophysiologic testing for risk stratifica tion in patients with chronic left ventricular dysfunction.…”