Ventricular tachycardia late after repair of congenital heart disease: efficacy of combination therapy with radiofrequency catheter ablation and class III antiarrhythmic agents and long-term outcome.

OBJECTIVE: This study investigated the treatment of ventricular tachycardia (VT) after repair of tetralogy of Fallot or double outlet of the right ventricle.
BACKGROUND: The ideal antiarrhythmic therapy for VT in patients after repair of congenital heart disease, especially without left ventricular dysfunction, has not yet been established.
METHODS: Seven consecutive patients (2 women and 5 men) with stable monomorphic sustained VT were investigated. The mean age was 25 +/- 7 years (range, 16-35 years). Four patients had undergone surgical repair of tetralogy of Fallot, and 3 had surgical correction of double outlet of the right ventricle at the mean age of 18 +/- 7 years (range, 9-27 years) before documentation of the arrhythmia.
RESULTS: The mean ejection fraction of the left ventricle was 60% +/- 8% (range, 50-72). Fourteen sustained monomorphic VTs were induced in 7 patients using programmed electrical stimulation. The mean cycle length of tachycardia was 346 +/- 77 milliseconds (range, 260-480 seconds). The site of the surgical correction of the right ventricle was associated with the origin of VT in all patients. Radiofrequency catheter ablation was attempted in 8 VTs in 7 patients: 7 clinical and 1 nonclinical VTs. In 6 patients, class III antarrhythmic agents were added because VT remained inducible after ablation. During a follow-up of 61 +/- 29 months (range, 15-110 months), there were no recurrences of VT.
CONCLUSION: In patients with drug-refractory VT originating from the right ventricle late after congenital heart disease, and when their left ventricular function do not deteriorate, combined therapy for radiofrequency catheter ablation with class III antiarrhythmic agents might effective and should be considered as a therapeutic option.