DURING the past several years the treatment of various cardiac arrhythmias by synchronized directcurrent countershock (cardioversion) has become well established.1 Although cardioversion has been performed in patients while they were awake,2 this method has not become widely accepted because of the discomfort experienced. In most instances, general anesthesia induced by a short-acting barbiturate has been used for the procedure. Since this usually requires the presence of an anesthesiologist, and since respiratory depression requiring assisted respiration may sometimes occur, other means of producing amnesia and analgesia have been sought. In a brief report,3 Nutter and Massumi described the intravenous use of diazepam (Valium) in 15 patients undergoing cardioversion, and reported that amnesia and analgesia for the procedure occurred in 14 cases. The present report describes the results of this approach in 35 patients. Procedure All patients undergoing emergency or elective cardioversion at the Yale-New Haven Hospital between January