Acute effects of ECT on cardiovascular functioning: Relations to patient and treatment variables

Abstract

In 34 patients with primary, major depressive disorder, randomly assigned to bilateral or right unilateral ECT, heart rate (HR) and blood pressure (BP) were assessed prior and following seizure induction at every treatment. In contrast to prior reports, no cumulative pattern was observed in HR or BP changes as a function of treatment number. Generally, treatment variables, including ECT modality (bilateral vs. unilateral), anesthetic agent (methohexital vs. pentothal), and prior subconvulsive stimulation in a session, had no effects on the magnitude of peak postictal increases in HR or BP. The peak changes were also unrelated to the history of cardiac illness, remission of depressive symptomatology, patient seizure threshold and patient seizure duration. Pre-treatment HR was strongly predictive of peak postictal change in both HR and BP, while pretreatment BP was not. Patients with high pre-ECT HR had smaller peak postictal HR and BP increases. The findings suggested that low dosage, titrated ECT has HR and BP effects similar to traditional high dosage techniques, and that pre-treatment HR is the best predictor of these effects.