Catheter ablation of an antidromic atrioventricular reentrant tachycardia using a slow, decrementally conducting accessory pathway in the great cardiac vein

Abstract

The inability to ablate left accessory pathways (APs) from endocardial approaches may suggest an epicardial location. We report on a 43‐year‐old woman presenting with a wide QRS tachycardia with Right Bundle Branch Block (RBBB) morphology, right inferior axis, and the “pattern break” appearance in V2 resembled the outflow tract ventricular tachycardia. An electrophysiology study confirmed an antidromic atrioventricular reentrant tachycardia using an antegrade slow, decrementally conducting AP that was successfully ablated in the great cardiac vein‐anterior interventricular vein junction after failure of endocardial approach.

Crazy accessory pathway- going round the bend!

“…Here we had a pattern break analogous to that described for ventricular tachycardia from the left ventricular summit area. Similar cases have been described in literature with respect to unusual location of accessory pathways [ [4] , [5] , [6] , [7] , [8] ]. Accessory pathways have also been described at left coronary sinus of Valsalva [ 9 ].…”

“…In a case reported by Madaddi [ 5 ], the maximally preexcited ECG pattern was similar to the baseline ECG in our case and ablation was carried out at a similar location. Another such case reported by Madaddi et al [ 8 ], there was slow antegrade conduction, no preexcitation in the baseline ECG and yet the tachycardia was antidromic, sensitive to isoproterenol. The tachycardia ECG during antidromic tachycardia showed negative delta in leads I, aVL and precordial pattern break in lead V2 which is similar to our patient.…”