Noninvasive assessment of electroconvulsive-induced changes in cardiac function.

Systolic time intervals were used to noninvasively evaluate the cardiac effects of electroconvulsive therapy (ECT) in eight psychiatric patients. ECT produced a hyperdynamic cardiac state in which there was a significant increase in blood pressure, a shortening of the pre-ejection period (PEP), and an increase in rate pressure product (RPP). Changes in the PEP and the RPP are compatible with increased cardiac contractility and oxygen consumption, respectively. These effects were apparently mediated by an ECT-induced increase in circulating catecholamines, particularly epinephrine.