Slow pathway cryoablation in a child with absent right superior caval vein and persistent left superior caval vein draining into the coronary sinus

A 12year old boy was referred to our institution for recurrent episodes of paroxysmal supraventricular tachycardia. The baseline ECG showed non-sinus atrial rhythm with heart rate of 75beats/min (Fig. 1-A). The echocardiogram revealed a normal cardiac structure with persistence of a left superior caval vein (PLSCV) draining into a dilated coronary sinus (CS). After a written informed consent, a transcatheter ablation procedure was planned because of agonist sport practice and parent choice. A fast anatomic map of the inferior caval vein, right atrium, CS and PLSCV was performed using an electroanatomic 3D mapping system (CARTO 3).