Transcoronary ethanol ablation of ventricular tachycardia via an anomalous first septal perforating artery

A 65-year-old man with a history of nonischemic cardiomyopathy and mild left ventricular dysfunction was referred for incessant drug-refractory ventricular tachycardia (VT) and implantable cardioverter-defibrillator (ICD) shocks. During electrophysiologic study with three-dimensional electroanatomic mapping (CARTO, Biosense-Webster, Diamond Bar, CA, USA), frequent nonsustained ventricular tachycardia (NSVT) and premature ventricular contractions (PVCs) of the same morphology as the clinical VT occurred (Figure 1A). Bipolar voltage maps failed to identify any low-voltage areas within the left or right ventricle. During PVCs, an early fractionated electrogram was identified at the inferobasal septum of the right ventricle (Figure 1B). Radiofrequency ablation using an externally irrigated catheter temporarily suppressed VT. Despite high-power prolonged ablation (50 W, 300 seconds) on both sides of the interventricular septum, NSVT and PVCs returned. In preparation for transcoronary ethanol ablation, the patient underwent coronary angiography with the ablation catheter positioned at the site of earliest activation in the right ventricle. Both the origins and course of the left anterior descending and circumflex coronary arteries were normal. However, no basal septal perforating arteries were identified (Figure 1C, dashed circle). The most proximal artery only corresponded to the midventricular septum. However, while attempting to cannulate the right coronary ostium, an anomalous origin of the first septal perforating artery, arising from the right sinus of Valsalva and supplying the basal ventricular septum, was identified (Figure 1D). The relevant branch of the septal perforating artery was selectively engaged using an angioplasty wire, and its distal tip corresponded to the tip of the ablation catheter (Figures 1E and 1F), which had been inserted at the site of earliest activation on the inferobasal septum. Over the guidewire, an angioplasty balloon was inflated in the first septal perforating artery, and 2 mL of injection of 1% lidocaine was injected. This resulted in transient suppression of PVCs. Therefore, 1 mL of 0.5% ethanol was injected into the target vessel. Subsequently, the clinical PVCs and NSVT were rendered noninducible. Two-dimensional contrast echocardiography (Definity, Lantheus Medical Imaging, North Billerica, MA, USA) demonstrated reduced perfusion of the basal inferior septum with borderline left ventricular function. Throughout the remainder of his hospital stay, the patient displayed no evidence of clinical PVCs or VT. He was discharged home 2 days postprocedure.