Objectives
Supraventricular and ventricular arrhythmias are a major cause of morbidity and mortality in adult patients with congenital heart disease (CHD). Intraoperative ablation offers an alternative to the complex surgical Cox-Maze procedure for these patients. We present the results of our preliminary experience with intraoperative monopolar irrigated radiofrequency ablation (IRA) in adults with CHD undergoing elective cardiac surgery.

Methods
Since September 2002, 58 adults with a mean age of 39 years with CHD underwent IRA during cardiac surgery. We performed 34 right-sided Maze procedures, 14 Cox-Maze III procedures and 10 right ventricular ablations. In addition, we implanted a pace-maker in 14 patients.

Results
Two patients (2/58; 3.4%) died of causes not related to the intraoperative ablation. Over an average follow-up period of 40 months the remaining 56 patients are alive in NYHA class I or II. All patients were discharged on oral antiarrhythmic treatment for 3-months. All patients underwent ambulatory 24-hrs Holter monitoring 3 and 6-months after the ablation procedure and 9 underwent programmed ventricular tachycardia stimulation 6-months post-procedure.
Forty-nine patients are still in spontaneous sinus rhythm, 3 are in sinus rhythm on chronic oral antiarrhythmic treatment for recurrence of atrial fibrillation, 3 are in stable atrial fibrillation and 1 has pacemaker rhythm. There were no complications from the IRA.

Conclusions
Intraoperative IRA is a safe and effective procedure to control arrhythmic problems in adults with CHD. This procedure should be taken into consideration when transcatheter ablation fails or when elective cardiac surgery is planned.