LOWN'S method1 for the termination of ectopic cardiac rhythms by means of synchronized direct current countershock has aroused understandable interest and enthusiasm. Particularly appealing has been the use of this technique in the treatment of atrial fibrillation where the difficulties of drug therapy with a high failure rate are well recognized. In addition to simplicity, safety, and immediate effect, the new system has yielded a distinctly higher percentage of conversions to sinus rhythm than could have been anticipated with the use of drugs. Perhaps the only disadvantage of countershock has been the need for brief anesthesia in many (probably not all) patients.
According to the inventor and his co-workers, who have presented the major evidence of effectiveness to date, the method was successful in terminating 89% of 65 episodes of atrial fibrillation among the first 50 patients they treated.2 This group was restricted, in a sense, in that all