Catheter ablation of ventricular tachycardia originating from a coronary arterial-right ventricle fistula:

A 38-year-old man was referred to our hospital for radiofrequency catheter ablation of recurrent ventricular tachycardia (VT) (Panel A). In cardiac magnetic resonance imaging and coronary artery 3D computed tomography, a left anterior descending coronary arterial-RV fistula was noted with its dilated terminal part forming the aneurysm (Panels B–E). Although in the first RV and LV mapping, the earliest activation area was at LV near the fistula with local potential 17 ms before QRS onset, ablation of this LV apical lesion did not terminate the VT. Because the patient refused cardiac surgery to obliterate the fistula, we performed a second mapping procedure of the coronary sinus branches. As soon as the ablation catheter entered the middle cardiac vein (MCV) (Panels F and G), a local potential 25 ms prior to QRS onset was recorded (Panels H and I). Ablation lesion (green point in Panel I) in MCV terminated the VT, rendering it non-inducible (four applications at 40°C/40 W). There was no arrhythmia recurrence during 6-month follow-up. To our knowledge, this is the first case report of successful catheter ablation for VT originating from a rare coronary arterial-RV fistula with an aneurysm near the middle coronary vein; epicardial ablation in MCV terminated the VT. The full-length version of this report can be viewed at: http://www.escardio.org/Guidelines-&-Education/E%E2%80%93learning/Clinical-cases/Electrophysiology/EP-Case-Reports.