Electrophysiology assessment and radiofrequency ablation of arrhythmias in adult patients with congenital heart defects: the Christchurch experience.

Introduction: Adults with congenital heart disease (CHD) frequently have cardiac arrhythmias, many of which are best treated with radiofrequency ablation (RFA). We present our experience in this group.
Methods: Retrospective chart based review of diagnosis, arrhythmia type, results of cardiac electrophysiological assessment, and procedural and long-term clinical success of radiofrequency ablation.
Results: Forty-five patients were identified with CHD and arrhythmias undergoing RFA; including surgically repaired atrial septal defects (21), Ebstein's anomaly (12), repaired transposition of the great arteries (3), repaired Tetralogy of Fallot (4), repaired ventricular septal defect (3), repaired coarctation (1) and unrepaired anomalous pulmonary venous anatomy (1). Arrhythmias were atrial flutter (24), atrial fibrillation (1), atrial tachycardia (3), atrioventricular nodal re-entrant tachycardia (5), and atrioventricular re-entrant tachycardia (12). Procedural success was ultimately obtained in 36 patients, with 6 having unsuccessful ablation and 3 an undetermined result. Twelve patients required a repeat procedure. One patient required a third procedure and had insertion of permanent pacemaker and atrioventricular nodal ablation. With follow-up (range 2-264 months) 31 patients (69%) remained in sinus rhythm, 9 have developed atrial fibrillation, 3 are in atrial flutter or atrial tachycardia, 1 patient reports ongoing palpitations with no documented arrhythmia and 1 patient has died. Procedural complications were major venous access bleeding (2), transient heart block during slow pathway ablation with late complete heart block (1).
Conclusions: The majority of arrhythmias in adult patients with congenital heart defects can be successfully treated with radiofrequency ablation at a relatively low risk.