Mapping and ablation of ventricular tachycardia using dual-energy lattice-tip focal catheter: early feasibility and safety study

Abstract

Background Catheter ablation is an effective treatment method for recurrent ventricular tachycardias (VT). However, at least in part, procedural and clinical outcomes are limited by challenges in generating an adequate lesion size in the ventricular myocardium. Objective We investigated procedural and clinical outcomes of VT ablation using a novel “large-footprint” catheter that allows the creation of larger lesions either by radiofrequency (RF) or by pulsed field (PF) energy. Methods In prospectively collected case series, we describe our initial experience with VT ablation using a lattice-tip, dual-energy catheter (Sphere-9, Medtronic), and a compatible proprietary electroanatomical mapping system (Affera, Medtronic). Results The study population consisted of 18 patients (aged 55±15 years, 1 woman, structural heart disease: 94%, ischemic heart disease: 56%, left ventricular ejection fraction: 34±10%, electrical storm: 22%) with recurrent sustained VTs and ≥1 previously failed endocardial RF ablation with conventional irrigated-tip catheter in 66% of patients. On average, 12±7 RF and 8±9 PF applications were delivered per patient. In 3/4 of patients undergoing percutaneous epicardial ablation, spasms in coronary angiography were observed after PF applications. All resolved after intracoronary administration of nitrates. No acute phrenic nerve palsy was noted. One patient suffered from a stroke that resolved without sequelae. Post-ablation non-inducibility of VT was achieved in 89% of patients. Ventricular-arrhythmia-free survival at three months was 78%. Conclusion VT ablation using a dual-energy lattice-tip catheter and a novel electroanatomical mapping system is feasible. It allows rapid mapping and effective substrate modification with good outcomes during short-term follow-up.