Background
Pulsed-field ablation (PFA), based on irreversible electroporation, was developed and first adopted clinically for atrial fibrillation, providing tissue-selective, largely non-thermal lesions with a favourable safety profile. Preclinical data suggest advantages for ventricular tachycardia (VT) ablation, where PFA penetrates dense scar that can limit thermal energy transfer in radiofrequency ablation (RFA). Combining the two energy sources at the same site has been shown to create even deeper lesions than either alone. A contact-force dual-energy catheter integrated with a 3D mapping system now allows switching between RFA and PFA within a single workflow, but real-world experience in ventricular arrhythmias remains limited. The aim of the study was to evaluate the feasibility and efficacy of dual-energy ablation - combining PFA and RFA - for VT ablation in re-interventions or cases with a suspected intramural origin.
Methods
Consecutive patients undergoing catheter ablation of ventricular tachycardia (VT) or premature ventricular complexes (PVC) were included in case of redo-ablation or suspected intramural origin. Dual-energy THERMOCOOL SMARTTOUCH SF (DE STSF) catheter and the TRUPULSE multimodality generator (Biosense Webster, Incwere used in combination with CARTO3D mapping system. PFA was applicated on RFA lesions. Close to His (<5 mm) no PFA was performed. For VT, acute outcome was assessed by programmed stimulation at the end of the procedure and classified as complete success (no VT inducible), partial success (clinical VT non-inducible but a non-clinical VT still inducible), or failure (clinical VT still inducible). For PVC ablation, acute success was defined as suppression of the targeted ectopy. Periprocedural complications and acute outcomes were recorded.
Results
Twenty-nine consecutive patients were included (VT 21, PVC 8; age 67 [56–74] years; 22 [76%] male; BMI 27.7 [24.7–32.6] kg/m²; LVEF 40 [26–45]). Underlying disease was predominantly structural in the VT cohort (dilated cardiomyopathy 52%, ischaemic cardiomyopathy 24%), whereas PVC patients were largely idiopathic with preserved ventricular function (LVEF 50 [37–59]). Overall, 63.1% of lesion deliveries were performed using RF energy and 36.9% using PFA.
Median procedure, mapping, ablation and fluoroscopy times were 125 [110–166], 29 [20–40], 29 [14–42] and 4.7 [2.8–8.9] minutes, respectively, with procedure and ablation times longer in VT than in PVC ablation.
In the VT cohort, acute outcome was a complete success in 18/21 (86%), partial success in 2/21 (10%), and failure in 1/21 (5%). PVC suppression was achieved in 8/8 (100%). Periprocedural complications occurred in 3/29 (10%) - atrioventricular block in 2 (7%) and pneumonia in 1 patient (3%) - with no pericardial tamponade, stroke, or in-hospital death. Follow-up data will be presented at DRT
Conclusion
Dual-energy (RF–PF) ablation with the DE STSF catheter was feasible for both VT and PVC ablation, with short procedure and fluoroscopy times, high acute effectiveness (complete VT non-inducibility in 86% and PVC suppression in 100%), and a favourable safety profile (no tamponade, stroke, or death). These early data support the feasibility of a combined RF/PFA workflow for ventricular arrhythmias; lesion durability and longer-term clinical outcomes warrant further follow-up.
