CARDIOVASCULAR RESPONSES TO TRANSCRANIAL ELECTRIC STIMULATION IN MAN AND DOG

Factors that might contribute to the mortality associated with electroconvulsive therapy were sought in a study of 400 treatments. Most of the patients received thiopental (average dose 400 mg.) intravenously before the treatment, and all received succinylcholine chloride and artificial ventilation with oxygen during the period of apnea. Vagal arrhythmias (marked tachycardia, occasional cardiac arrest) never occurred in patients who had received atropine but occurred frequently in patients who had not. Extravagal arrhythmias also occurred frequently and were not uniformly preventable by either chlorpromazine or quinidine therapy. All patients had transitory increases of systolic blood pressure. The increases were about half as great in patients who had received tetraethylammonium chloride as in patients who were not so protected. Experiments involving bilateral adrenalectomy and transection of the spinal cord in dogs corroborated the impression that both vagal and extravagal mechanisms are activated by electroconvulsive treatment and can be depressed by appropriate medication.