Radiofrequency Ablation of Accessory Pathways in Children with Complex Congenital Cardiac Lesions: A Report of Three Cases
A 7-year-old girl, weighing 21 kg, presented with frequent palpitations and documented narrow complex tachycardia. Her electrocardiogram during sinus rhythm showed a manifest left lateral AP (). In the past, she had been diagnosed to have tricuspid atresia (type IIb) with D-transposition of the great arteries, a large ventricular septal defect, and pulmonary hypertension (). She had undergone pulmonary artery banding, followed by Glenn shunt, and was awaiting total cavopulmonary connection. She had associated severe scoliosis. We conducted an electrophysiological study and documented both an orthodromic atrioventricular reentrant tachycardia and atrial tachycardia with a rapid conduction over the AP. There was no direct access to the right ventricle, and the ventricular catheter was placed via the right atrium into the left atrium and through the atrial septal defect before it was positioned in the left ventricle. Endocardial ablation on the mitral annulus had previously failed at another center. We mapped the mitral annulus again during sinus rhythm: no good signals could be recorded and, thus, no energy was delivered there. We successfully carried out the ablation of the sub-epicardial AP in the coronary sinus near the origin of the middle cardiac vein (). Interestingly, atrial tachycardia was easily inducible before ablation, but it could not be induced after the elimination of the AP (). The P-wave morphology during atrial tachycardia was in favor of a left atrial origin. The procedure time was 120 minutes, and the fluoroscopy time was 35 minutes.