Percutaneous Epicardial Mapping and Ablation of a Posteroseptal Accessory Pathway

Abstract

A 20-year-old man with no past medical history experienced a syncopal episode. He was found to be pulseless, and cardiopulmonary resuscitation was initiated. When emergency medical service arrived, rhythm strip showed an irregular wide-complex tachycardia consistent with preexcited atrial fibrillation with cycle length as short as 180 ms (333 beats per minute) (Figure 1A). He was defibrillated successfully into sinus rhythm. A 12-lead ECG showed sinus rhythm with PR interval of 110 ms, delta waves and pseudo-infarct pattern in the inferior leads consistent with a posteroseptal accessory pathway (Figure 1B). He was referred to us for an electrophysiology study. Figure 1. A, Rhythm strip of patient during the cardiac arrest, showing irregular wide-complex tachycardia very suggestive of preexcited atrial fibrillation. B, 12-lead ECG after resuscitation. The short PR interval, delta wave and pseudo-infarct pattern in the inferior leads are consistent with the presence of a manifest accessory pathway (Wolff-Parkinson-White Syndrome). During the procedure, extensive mapping in the right atrium, the coronary sinus (CS) and its branches, and the left atrium (via transseptal approach) was performed. A CS angiogram showed the presence of a diverticulum. The area of earliest ventricular …