Transient changes in pacing and sensing parameter following ablation using dual-energy lattice-tip system for ventricular tachycardia

Background Transient changes in pacing and sensing parameters have been reported after conventional radiofrequency ablation. However, the impact of novel pulsed field ablation (PFA) energy on device leads remains unclear. The dual energy lattice tip ablation system employs a unique energy configuration, and its effects on lead parameters warrant careful evaluation. Methods This study included 61 patients (age 60 ± 14 years, 52 men [82.3%], ICD: 39, CRT: 22) who underwent ventricular tachycardia ablation using the dual-energy lattice tip ablation system between February 2024 and October 2025. Pacing threshold, R-wave sensing amplitude, and right ventricular (RV) lead impedance were measured before, immediately after, and 3 months after the procedure and compared among these time points. For pacing threshold analysis, values measured with pulse widths other than 0.4 ms were converted to the equivalent threshold at 0.4 ms using the strength–duration (Lapicque/Weiss) model with a chronaxie of 0.4 ms. Result In 61 patients, the pacing threshold (converted to 0.4 ms) increased immediately after ablation (0.94 ± 0.44 V before vs 1.08 ± 0.61 V after, p = 0.034) and returned to baseline at 3 months (0.99 ± 0.56 V, p = 0.47 vs baseline). Of interest, in two patients (3.3%) the pacing threshold acutely increased substantially from 1.25 to 3.0 V and from 1.7 to 3.8 V, respectively. These changes were not associated with PFA close to the tip of the electrode. The R-wave amplitude significantly decreased after the procedure (12.75 ± 5.66 mV before vs 11.06 ± 5.44 mV after, p < 0.001) and recovered to baseline by 3 months (12.84 ± 5.91 mV, p < 0.001 vs post-procedure). The RV lead impedance decreased immediately after ablation (477.98 ± 124.09 Ω before vs 425.83 ± 108.16 Ω after, p < 0.001) and subsequently increased at 3 months (451.78 ± 98.63 Ω, p < 0.001 vs post-procedure; p = 0.024 vs baseline). Conclusion Ablation using a dual-energy lattice tip system can transiently worsen pacing and sensing parameters immediately after the procedure. Although these changes can be substantial in individual patients, the pacing parameters tend to improve and stabilize during follow-up. Clinicians should be aware of such acute alterations when performing ablation with this novel energy delivery system.