Abstract 4362029: Endo-Epicardial Ablation for Recurrent Scar-Mediated Ventricular Tachycardia: A Case Report

Introduction: Endo-epicardial ablation is used for a wide variety of cardiac arrhythmias including idiopathic and scar-related ventricular tachycardias (VT). Patients who have extensive scar tissue or adhesions from prior cardiac surgeries might not be candidates for percutaneous access and require collaboration with cardiothoracic surgery prior to ablation. Case: A 61-year-old male with history of CAD (3-vessel CABG in 2005 and four subsequent PCIs), HFrEF with LBBB (status post CRT-D), and recurrent VT (with four endocardial VT ablations) presented with palpitations and an episode of syncope. ECG and device interrogation confirmed recurrent slow VT (figure 1). He was treated with manual ATP via device interrogation and started on a lidocaine infusion. He was euvolemic and labs were unremarkable. Left heart catheterization three months prior showed a patent LIMA-LAD graft, occluded OM vein graft, severe proximal LAD in-stent restenosis treated with PCI, and no additional revascularization targets. The decision was made to pursue endocardial and epicardial ablation due to prior treatment failure. The procedure was performed in the EP lab with transesophageal echocardiography for hemodynamic monitoring. Preemptive common femoral artery and vein sheaths were inserted for ECMO backup. A left thoracotomy was performed with subsequent lysis of pericardial adhesions. Intraoperatively he was in stable VT (figure 2). Epicardial mapping was performed with an HD GRID-X catheter (Abbott Medical) followed by LV endocardial activation mapping. This demonstrated a central channel in the inferior wall (Figure 3). Epicardial entrainment was performed which confirmed localization within the critical isthmus of the reentry circuit. Radiofrequency (RF) ablation was performed resulting in VT termination, with additional epicardial cryoablation performed afterwards. Endocardial RF ablation was performed targeting low amplitude fractionated EGMs opposing the epicardial ablation site. Following ablation, VT was non-inducible with programmed stimulation down to 400/200/200/200 ms. He was discharged on post-operative day 4 without complications or recurrence. Discussion: We present a case of recurrent VT, refractory to endocardial ablation, in the setting of extensive cardiac surgical history. Collaboration between electrophysiology and cardiothoracic surgery regarding options for epicardial ablation in this high-risk patient population is necessary to ensure optimal outcomes.