Intraoperative radiofrequency ablation of the atrium: effectiveness for treatment of supraventricular tachycardia in congenital heart surgery.

Background: Supraventricular tachycardia (SVT) is common in surgical patients with congenital heart disease. Ablation and maze operations have been shown to be effective in treating SVT, but these procedures can be complex and time-consuming because of variable anatomy and a thickened right atrium. To simplify and shorten these procedures, we used a long, flexible radiofrequency probe capable of producing long ablation lines quickly and effectively. We report the initial results with this procedure.

Methods: Six patients aged 6 weeks to 40 years with refractory SVT were referred for reoperation for repair of complex congenital heart disease (transposition of the great vessels, Ebstein's anomaly, single ventricle, tetralogy of fallot). Intraoperative radiofrequency ablation was performed in the right atrium for refractory SVT as an adjunct to surgical reconstruction (redo Fontan, right atrial reduction plasty, right ventricular outflow tract reconstruction, tricuspid repair). Lesions were made with a radiofrequency probe using temperatures of 70 degrees C for 60 seconds. Lesions were placed between the coronary sinus and the tricuspid valve, between the tricuspid valve and the inferior vena cava, between the atrial septal defect and the superior and inferior vena cava in patients with intraatrial reentry tachycardia/atrial flutter, and at the location of the accessory pathway in a patient with Wolff-Parkinson-White syndrome. The long, flexible probe has multiple independently controlled segments allowing ablation lesions that conform to the atrial morphology.

Results: An average of five intraoperative radiofrequency ablation lesions per patient were made. Average time for ablation was 14 minutes. With up to 25 months' follow-up, 5 patients are in sinus rhythm, and 1 is in a paced atrial rhythm. The patient with Wolff-Parkinson-White syndrome showed no preexcitation after operation. No complications resulting from intraoperative radiofrequency ablation were encountered.

Conclusions: Intraoperative radiofrequency ablation in the atrium is a safe, effective, and expeditious procedure for control of SVT in patients undergoing reoperation for congenital heart disease with refractory SVT.