Atropine premedication and the cardiovascular response to electroconvulsive therapy.

A report by the Royal College of Psychiatrists recommended avoiding atropine premedication during electroconvulsive therapy (ECT). We have examined the cardiovascular effects of ECT with or without atropine premedication. Consenting patients (n = 30) were allocated randomly before their third ECT session to receive atropine or no premedication. The rate pressure product (RPP) was recorded before anaesthesia, before ECT stimulus and at 1-min intervals thereafter for 5 min. Patients who did not receive atropine had significantly lower RPP values after all stimulus recordings. Administration of atropine or not explained 32% of the variance of summated RPP after the stimulus. There was no clinically significant bradyarrhythmia in those who did not receive atropine. Our findings support the recommendation of the Royal College of Psychiatrists. The study suggests that when threshold determination is not needed, avoiding atropine effectively contains potentially harmful cardiovascular responses.