Elective Countershock in Unanesthetized Patients with Use of an Esophageal Electrode

Abstract

A new electrode arrangement for the administration of elective direct-current countershock was studied, in which one electrode was placed in the esophagus, adjacent to the heart, and the other on the precordium. Thirteen patients with chronic atrial fibrillation were converted to sinus rhythm by the esophageal technic. Though the majority were, on clinical grounds, difficult cases for conversion, 11 were converted with shocks of 40 watt-seconds or less, and two with 60, after 40 failed. Five patients were defibrillated by both the esophageal and the conventional, anteroposterior chest technics; the energy requirement with the esophageal method averaged less than one third of that with the conventional one. Four patients received 40, and one 30 watt-second shocks without anesthesia; all five tolerated the shocks well, and three of four who had had countershock previously under anesthesia, expressed preference for the esophageal technic without anesthesia in the future. All patients were observed carefully for any symptoms suggestive of esophageal injury or dysfunction. None such occurred, either immediately or within 4 months. We conclude that this technic may have a place in elective countershock in that it may allow cardioversion to be undertaken in many patients who would otherwise require anesthesia.