Changes of cardiac autonomic nervous activity during electroconvulsive therapy

Abstract

There have been few reports about the changes of autonomic nervous activity during ECT (electroconvulsive therapy). We evaluated heart rate and analysis of heart rate variability (HRV) sequentially using Memcalc Bonarylight software to study these autonomic nervous changes. Heart rate and HRV assessments were performed in three patients (two depression patients, and one schizophrenia patient), suggesting the triphasic stages of cardiac autonomic activity following a seizure. Just after ECT stimulus onset, bradycardia or sinus arrest was observed (the first stage) followed by increase of LF/HF (the second stage). Continuously, HF was increased while LF/HF was decreased (the third stage). Although the first stage and the second stage have been well investigated, this is the first description that elucidated parasympathetic nervous dominance separately from the reduction of sympathetic nervous activity in the third stage using HRV. Future study is needed to determine whether these triphasic stages of cardiac autonomic nervous activity are related to prognosis of ECT treatment and whether they predict an appropriate number of ECT session.