Feasibility and safety of a novel very-high-power short-duration ablation strategy for superior vena cava isolation

<h2>Abstract</h2><h3>Background</h3> The optimal radiofrequency (RF) settings for superior vena cava isolation (SVCI), including RF delivery to the lateral superior vena cava (SVC) segments which are associated with a risk of phrenic nerve injury (PNI), remain uncertain. <h3>Objective</h3> This study aimed to evaluate the clinical feasibility and safety of a novel RF setting of 70 W for 4 s for SVCI. <h3>Methods</h3> A total of 148 patients undergoing initial SVCI were retrospectively analyzed: 77 received 70 W/4 s ablation (70 W group), and 71 received conventional middle-power middle-duration ablation (30–40 W group). Between-group comparisons were performed for procedural outcomes, lesion characteristics, and complications. <h3>Results</h3> Procedural success was achieved in all patients in the 70 W group and 96% of the 30–40 W group (p = 0.11). The 70 W group demonstrated significantly shorter SVCI time (median 2.6 vs. 5.8 min, p < 0.001), shorter RF duration (36 vs. 161 s, p < 0.001), and lower RF energy (2313 vs. 5327 J, p < 0.001) than the 30–40 W group. Both groups had comparable first-pass SVCI rates (97% vs. 92%, p=0.15) and acute reconnection rates after isoproterenol loading (2.6% vs. 9.9%, p=0.09). Neither group had major complications, including PNI, cardiac tamponade, or sinus node injury. <h3>Conclusion</h3> SVCI using 70 W/4 s ablation achieved comparable procedural success with significantly reduced ablation time and energy without increasing the risk of PNI even in the lateral SVC segment.