1 From the Cardiopulmonary Laboratory, U. S. Public Health Service Hospital, Staten Island, New York.
The ability of diphenylhydantoin to prevent arrhythmias induced by synchronized direct current shocks after digitalis sensitization was evaluated. In the control state, an average of 155 watt-seconds was required to produce ventricular tachycardia. Immediately after recovery from digitalis toxicity, an average of 23 watt-seconds produced ventricular tachycardia. The administration of diphenylhydantoin at this time immediately increased the threshold required for ventricular tachycardia to an average of 363 watt-seconds. In eight studies, diphenylhydantoin was given during cardioversion-induced ventricular tachycardia and converted all cases to regular sinus rhythm. These findings indicate that diphenylhydantoin may be of prophylactic value prior to direct current cardioversion in a digitalized patient. Conversely, diphenylhydantoin would also be useful in the management of ectopic beats that may occur in digitalized patients after cardioversion.
© 1968 American Heart Association, Inc.
Diphenylhydantoin Prevention of Arrhythmias in the Digitalis-Sensitized Dog after Direct-Current Cardioversion
Key Words: Ectopic beats • Electrical energy threshold • Ventricular automaticity