Effect of Atropine Premedication on Cardiac Autonomic Function During Electroconvulsive Therapy: A Randomized Crossover Study

Objectives Electroconvulsive therapy (ECT) results in significant cardiovascular changes. The acute cardiac autonomic changes during ECT remain unexplored. The primary objective of this study was to compare autonomic dysfunction with and without atropine premedication during ECT and secondarily to evaluate dysautonomia across psychiatric diagnoses before and after ECT. Methods In this crossover study, 41 psychiatric patients were monitored during 82 ECT sessions. Patients were randomized either to receive atropine or not to receive atropine during their second ECT session and were crossed over during their third session. Heart rate, blood pressure, and oxygen saturation were continuously monitored from stimulus application until 300 seconds after ECT. Demographic characteristics and ANSiscope indices derived pre- and post-ECT were collected. Results Autonomic dysfunction (%) before ECT was similar between atropine and no-atropine sessions (32.4 15.7 vs 32.8 +/- 16.7; 95% confidence interval, -7.6 to 6.7; P = 0.90) but increased significantly after ECT to 60.9 +/- 16.3 and to 47.0 +/- 17.3, respectively, and this difference was significant (95% confidence interval, 6.5-21.3; P < 0.001). There was no difference in the autonomic function across psychiatric diagnoses both before (P = 0.07) and after ECT (P = 0.12). Conclusions Cardiac autonomic dysfunction worsens after ECT in patients with psychiatric illnesses and to a significantly greater extent with atropine premedication. The degree of dysautonomia is similar across various psychiatric diagnoses both before and after ECT. Atropine premedication during ECT should be restricted to select patients susceptible to bradyarrhythmia and could be avoided in others.