Ablation of ventricular tachycardias by dual-source, lattice-tip focal ablation catheter: effect of energy source on myocardial lesion size and hemolysis

Background Catheter ablation is an effective treatment method for recurrent ventricular tachycardias (VT) using radiofrequency (RF) energy as a gold standard. However, procedural and clinical outcomes are limited by challenges in generating an adequate lesion size in the ventricular myocardium. To overcome this, newer modalities such as pulse field (PF) ablation emerged. Yet, its effect on the ventricular myocardium lesion size and hemolysis has not been determined. Purpose Quantify the effect of energy source (RF vs PF) on the extent of myocardial lesion and hemolysis using a novel "large-footprint" catheter. Methods In a prospectively collected cohort, patients underwent VT ablation using a lattice-tip, dual-energy catheter and a compatible proprietary electroanatomical mapping system. For endocardial ablation, patients were ablated using RF (30 sec per application) or PF energy (5.5 sec per application) or their combination at the operator's discretion. Only PF energy was used in the epicardium. High-sensitivity troponin T (hsTnT) and free hemoglobin were analyzed to assess myocardial lesion size and degree of hemolysis. Results The study population comprised 51 patients (aged 58±16 years, 6 women). The baseline and procedural characteristics are listed in the Table. There was no statistically significant difference in total troponin release between the PF ablation group and the PF+RF or RF-only ablation group (P=0.55). However, according to a linear regression model (multivariate R=0.47; P=0.003), a single RF application was associated with a twofold increase of hsTnT [+62 (95% CI: 40-84) ng/L] compared to a PF application [+31 (95% CI: 23-38) ng/L]. Also, no clinically significant hemolysis was detected in the whole cohort, as documented by the low free hemoglobin after the procedure (60±56 mg/L). The acute outcomes of the ablation were favorable irrespective of the energy used. Conclusion VT ablation using the dual-energy lattice-tip catheter and the novel electroanatomical mapping system is feasible and effective. RF ablation is associated with significantly higher troponin release per application compared to PF ablation. Ablation with neither energy is associated with significant hemolysis.