Successful radiofrequency catheter ablation of sinoatrial nodal reentrant tachycardia after a total cavo-pulmonary connection procedure with an extra-cardiac conduit.

We report a tachyarrhythmia case of a 32-year-old female with a single ventricle and heterotaxy syndrome. She had surgery involving a total cavo-pulmonary connection procedure using an extra-cardiac conduit (EC) at the age of 17 years. A tachycardia was repetitively induced with single atrial extrastimuli. An activation map was created revealing a centrifugal propagation pattern from the high atrial wall adjacent to the EC. At that site, a structure resembling the crista terminalis was recognized with intracardiac echocardiography. Therefore, high output energy was required to eliminate the tachycardia. It was thought to be a sinoatrial nodal reentrant tachycardia. <Learning objective: Radiofrequency catheter ablation (RFCA) of supraventricular tachycardia (SVT) after a total cavo-pulmonary connection with an extra-cardiac conduit is challenging and the diagnosis of the SVT is difficult. However the electrophysiological features observed during the electrophysiological study using a three-dimensional mapping system, anatomical features observed with intracardiac echocardiography, and pharmacological features seen during a rapid intravenous injection of adenosine triphosphate can lead to an accurate diagnosis, and moreover lead to a successful RFCA.>.