Introduction
Arrhythmia contributes significantly to morbidity and mortality of patients with congenital heart disease (CHD) or cardiomyopathy (CMP). It also has the potential to worsen symptoms and is particularly detrimental to patients with advanced heart failure awaiting cardiac transplantation. We report our experience using catheter ablation to treat recurrent arrhythmia in patients with CHD or CMP considered for transplantation.

Methods
Five consecutive patients (3 female, mean age 47.8 ± 12.8 years) with complex CHD or CMP (tricuspid atresia, mitral atresia, double inlet left ventricle, arrhythmogenic right ventricular cardiomyopathy, left ventricular non-compaction) presented with either atrial (n = 3) or ventricular (n = 2) arrhythmias. All ablations were guided by three-dimensional (3D) electro-anatomical mapping, plus remote magnetic navigation in 3 patients.

Results
Patients underwent a median of 2 ablation procedures for a total number of 26 tachycardias. None of the 5 patients experienced further arrhythmia at a median of 939 days (range 4–1375) from their last ablation. During a median follow up of 31 months (range 1–70), three patients underwent successful transplantation at 1375, 1062 and 321 days following their last ablation. One patient with a Fontan circulation died from hepatic cancer and one from end-stage heart failure despite urgent transplant listing.

Conclusions
Catheter ablation is feasible in complex cardiac patients considered for heart transplantation and should be offered for rhythm management and patient optimization until a suitable donor is found.