Preexcitation syndromes: surgical ablation therapy. The Cleveland Clinic experience

Thirty-four patients with preexcitation syndrome had surgical ablation of the accessory atrioventricular connection. All presented with sustained symptomatic arrhythmias, which had resulted in syncope in seven patients and aborted sudden cardiac death in four. Arrhythmias induced at electrophysiologic evaluation included orthodromic reciprocating tachycardia in 32 patients, antidromic reciprocating tachycardia in five patients, and atrial fibrillation in 29 patients. A single accessory atrioventricular connection was located in 32 patients and two patients had multiple accessory connections. The accessory connection was located with intraoperative mapping in all patients and the pathway was successfully ablated in 32. Eleven patients underwent a transmural approach and 23 patients underwent an epicardial dissection. Cryotherapy was used in 22 patients. After a mean follow-up of 32 months, 28 patients were free from all arrhythmias without drug therapy. Six patients continued to have symptomatic arrhythmias but only one case was suspected to be secondary to unsuccessful ablation of the accessory connection. One patient with heart block induced at the surgical procedure is dependent upon a pacemaker.