Cryoablation of septal pathways in patients with supraventricular tachyarrhythmias.

Eighteen patients with supraventricular tachycardia refractory to medical therapy underwent preoperative electrophysiological study and subsequent operation. There were 6 female and 12 male patients ranging in age from 1.5 to 31.6 years (mean age, 11.9 +/- 7.8 years). Eleven had classic Wolff-Parkinson-White syndrome with intermittent tachycardia, and 7 had a form of permanent junctional reciprocating tachycardia. Five had impaired left ventricular function preoperatively. The location of the accessory conduction pathway was anteroseptal in 3, posteroseptal in 12, and both anteroseptal and posteroseptal in 3 patients. Pathway location was confirmed by intraoperative mapping in all patients. The pathways were ablated utilizing a cryoprobe at -70 degrees C. All patients survived the operation, had immediate abolishment of delta waves and tachycardia, and were considered cured at the time of hospital discharge. Sixteen (89%) remain cured at a mean follow-up of 16.9 months. One patient with a posteroseptal pathway no longer has a delta wave but has had poorly documented episodes of tachycardia and is taking medication. One other patient with both anteroseptal and posteroseptal pathways had a recurrent delta wave 6 months postoperatively but has had no tachycardia and is asymptomatic without medication. No patient experienced heart block. Ventricular function has returned to normal in all 5 patients with impaired function preoperatively. Cryoablation is an effective method of abolishing accessory conduction pathways located in the anteroseptal or posteroseptal region. The method is easy, and results are comparable with those of other techniques previously described.