Radiofrequency ablation of accessory pathways in a toddler with Ebstein’s anomaly and functional single ventricle physiology

A 3-year-old girl, weighing 11 kg, with a diagnosis of Ebstein’s anomaly was referred to our center due to recurrent supraventricular tachycardia (SVT) attacks resistance to multidrug medical therapy. She had a modified Blalock-Taussig shunt operation in the neonatal period, and thereafter suffered from recurrent SVT attacks compromising hemodynamics, requiring cardioversion. A surface electrocardiogram showed preexitation consistent with Wolf–Parkinson–White Syndrome. An electrophysiology study with RF ablation of AP followed by hemodynamic study before bidirectional Glenn operation was planned. The electrophysiology study was conducted under general anesthesia. A three-dimensional mapping with the ESI system (EnSite System, St. Jude Medical, Minneapolis, MN, USA) was utilized during the procedure. Recurrent SVT attacks induced during diagnostic catheter placement and causing hypotension and desaturation were stopped with adenosine administration. Baseline measurements were performed (AH: 82 ms, HV: 0 ms, BCL: 700 ms, PR: 115 ms, QRS: 132 ms, and QT: 450 ms). Standard atrial stimulation protocol was carried out and orthodromic SVT with narrow QRS and tachycardia cycle length of 324 ms was induced. Because of hemodynamic compromise during SVT ESI, system mapping was done only for a short duration and the earliest VA conduction was found in right posteroseptal region of the tricuspid annulus with 63 ms (PERP: 320 ms, shortest preexited R-R interval in AFİB: 380 ms). This region was marked via ESI system (Fig. 1) and a 5F RF ablation catheter was advanced into the right atrium positioned directly to this site. With a 50 W-50 C0 application for 2 s, AP was lost and most of the preexitation on the 12-lead electrocardiogram was also lost Case Reports Anatol J Cardiol 2017; 18: 158-62