Ictal physiological characteristics of remitters during bilateral electroconvulsive therapy

Ictal heart rate (HR) and postictal suppression in ictal EEG are believed to be predictive of the therapeutic efficacy of eletroconvulsive therapy (ECT) for depression. However, regarding ictal peak HR, previous studies investigated ictal HR on only one or two occasions during the course of ECT. We prospectively examined whether two physiological parameters, ictal peak HR and postictal suppression in ictal EEG, during every session, including those with abortive seizure, predicted ECT efficacy. Ictal peak HR and postictal suppression index were analyzed in 53 consecutive inpatients with depression using generalized estimating equations analysis, which corrects for the repeated nature of the observations. The peak HR and postictal suppression index were associated with therapeutic efficacy in remitters during sessions with adequate seizure. The physiological characteristics of the remitters included lower peak HR, lower stimulus energy, and higher postictal suppression index. However, these results could not be generalized, and are limited to non-atropine conditions and bilateral ECT.