OC44 VENTRICULAR TACHYCARDIA SURGICAL ABLATION IN REPAIRED TETRALOGY OF FALLOT PATIENTS

Abstract

Background and Aim: Arrhythmias are the main causes of mortality in repaired TOF patients and ventricular tachycardia, due to abnormal electrical conduction near patches and surgical incisions, is refractory to medical therapy. The aim of the study is to evaluate the effectiveness of surgical ventricular RF ablation during pulmonary valve replacement. Methods: 20 patients (median age 37,5 y) in 2004–2013 underwent re-operation for symptomatic pulmonary valve regurgitation with RF ablation, 28 (16–39) years after first repair. Inducible VT was demonstrated during preoperative electrophysiological study in all. Median QRS was 178 (100–268) ms. Right ventricular dilation and dysfunction were present in all, with moderate-to-severe tricuspid regurgitation in 20%. Eleven patients showed spontaneous ventricular arrhythmia, 5 had preoperative ICD, and one presented out-of-hospital cardiac arrest. Surgical ablation of the slow-conducting isthmus between the VSD patch and the pulmonary annulus was performed with linear RF lesions. All patients underwent clinical evaluation, echocardiography and Holter-ECG at 1-3-6 months together with electrophysiological study after 6 months. Results: 16 patients underwent RVOT reduction and 4 TV repair. Median follow-up of 6.5 years was complete. 1 patient with pulmonary artery occlusion died on V-V ECMO for respiratory failure. No late mortality was observed. Residual inducible VT was present in 3/19 patients, whom received ICD as primary prevention. Freedom from ventricular arrhythmia was respectively 94% and 89.5% at 1 and 5 years of follow-up. Conclusion: Pulmonary regurgitation and ventricular dysfunction are correlated with SCD. Ablation of slow-conducting isthmus between the pulmonary valve and VSD patch prevents ventricular arrhythmias.