Figure 1.

A: Midmyocardial septal scar and mapping catheters positioned to map ventricular tachycardia (VT) activation. A duodecapolar catheter (DD) was positioned along the right ventricular septum and ablation catheter (Abl) on the left ventricular septum via transseptal approach. A 2F mapping catheter was positioned with the 2 most distal electrodes within the septal perforating vein (SPV). B: An intraseptal fractionated late potential is recorded from within the SPV, which yields a near-perfect pace map match for the clinical induced VT with stimulus-to-QRS latency. GCV = great cardiac vein; LAO = left anterior oblique; SP = septal perforator vein; RAO = right anterior oblique.