Catheter Technique for Closed-Chest Ablation of the Atrioventricular Conduction System: A Therapeutic Alternative for the Treatment of Refractory Supraventricular Tachycardia

This report describes a catheter technique for ablating the His bundle and its application in nine patients with recurrent supraventricular tachycardia that was unresponsive to medical management. A tripolar electrode catheter was positioned in the region of the His bundle, and the electrode recording a large unipolar His-bundle potential was identified. In the first patient, two shocks of 25 and 50 J, respectively, were delivered by a standard cardioversion unit to the catheter electrode, resulting in an intra-His-bundle conduction defect. Subsequent delivery of 300 J resulted in complete heart block. In the next eight patients, an initial shock of 200 J was used. The His bundle was ablated by this single shock in six of these patients and by an additional shock of 300 J in one. In the remaining patient, conduction in the atrioventricular node was modified, resulting in alternating first and second-degree atrioventricular block. A stable escape rhythm was preserved in all patients. The procedure was well tolerated, without complications, and all patients have remained free of arrhythmia, without medication, for follow-up periods of two to six months. (N Engl J Med. 1982; 306:194–200.) Patients with recurrent supraventricular tachyarrhythmias occasionally become disabled because available pharmacologic agents are ineffective or poorly tolerated, and pacemaker techniques fail to control recurrences. In the absence of an accessory atrioventricular pathway as the underlying cause of arrhythmia, surgical interruption of the atrioventricular conduction system with implantation of a permanent ventricular pacemaker has been shown to provide effective therapy. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 A variety of experimental techniques have been proposed to ablate the conduction system, 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 but to date only open-chest approaches have been used to accomplish interruption of the atrioventricular node and His bundle in human beings. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 This report describes a technique for . . .