Introduction: The ablation index (AI)-guided high-power ablation for pulmonary vein isolation (PVI) appears to be a novel strategy in treating atrial fibrillation (AF). This study aimed to evaluate the feasibility and safety of superior vena cava isolation (SVCI) by using an AI-guided high-power ablation strategy among patients with AF after PVI. Methods and Results: Data from 53 patients with AF were collected. Mapping and ablation of SVC were performed after PVI. The ablation power was set to 45 W and the ablation procedure was guided by AI. The SVC was divided into six segments in a cranial view. Applications and locations of radiofrequency (RF) were recorded. The RF applications and AI values in different SVC walls were compared and analyzed. SVCI was performed in 46 patients and electrical SVCIs were successfully achieved in all patients with a mean of 7.6 ± 2.9 RF applications. The mean time of the SVCI procedure was 9.5±4.5 min. The RF applications were located on different walls (anteroseptal anterior wall, 20/46 sites [43.5%]; posteroseptal wall, 38/46 sites [82.6%]; posterior wall, 40/46 sites [87.0%]; anterior walls, 37/46 sites [80.4%]; anterolateral wall, 27/46 sites [58.7%]; posterolateral wall, 23/46 sites [50%]). The mean AI value in septal, posterior, and anterior walls was higher than that of the lateral wall (392±28 vs 371±37, P < 0.001). There was no complication in any cases. Conclusion: AI-guided high-power ablation is a feasible and safe strategy for performing SVCI. The RF applications and AI value in different SVC walls varied.

Objectives: The ablation index (AI)-guided high-power ablation for pulmonary vein isolation (PVI) apears to be a novel strategy in treating atrial fibrillation (AF). This study aimed to evaluate the feasibility and safety of superior vena cava isolation (SVCI) by using AI-guided high-power ablation strategy among patients with AF after PVI. Methods: Data from 53 patients with AF were collected. Mapping and ablation of SVC was performed after PVI. The ablation power was set to 45 W and the ablation procedure was guided by AI. The SVC was divided into six segments in a cranial view. Applications and locations of radiofrenquency (RF) was recorded. The RF applications and AI value in different SVC walls were compared and analyzed. Results: SVCI was performed in 46 patients and electrical SVCIs were successfully achieved in all patients with a mean of 7.6 ± 2.9 RF applications. The mean time of SVCI procedure was 9.5±4.5 min. RF applications at anteroseptal wall was 38 (10.8%) points in 20 (43.5%) patients, posteroseptal wall was 74 (21.0%) points in 38 (82.6%) patients, posteral wall was 81 (22.9%%) points in 40 (87.0%%) patients, anteroseptal wall was 72 (20.4%) points in 37 (80.4%%) patients, anterolateral wall was 45 (12.7%) points in 27 (58.7%) patients, anteroseptal wall was 43 (12.2%) points in 23 (50.0%) patients. The mean AI value in septal, posterior and anterior walls was higher than that of lateral wall. There was no complication in any cases. Conclusion: AI-guided high-power ablation is feasible and safe strategy in performing SVCI. The RF applications and AI value in different SVC walls varied.

Abstract Background: Contact-force sensing catheters are widely used in catheter ablation. The technique of high-power ablation has gained a growing attention in recent years. Our purpose of this meta-analysis is to compare the efficacy and safety between higher-power and conventional power ablation of atrial fibrillation (AF) by contact-force sensing catheters. Methods: We identified studies through searching MEDLINE, EMBASE, the Web of Science, Scopus and the Cochrane Library from inception up until July 2020. The primary outcomes were the recurrence of atrial tachyarrhythmia and complications. The secondary outcomes were acute reconnections of pulmonary veins(PVs), ablation time, and the total procedural time. Results: We identified four nonrandomized, observational studies (nROS) involving 231 patients with high-power ablation and 239 patients with conventional power ablation. There were insignificant differences in the recurrence rate of atrial tachyarrhythmia (14.2% versus 20.5%, OR: 0.64, 95%CI: 0.39 to 1.04, Z = 1.82, P = 0.07) and clinical complications (1.7% versus 2.5%, OR: 0.72, 95%CI: 0.21 to 2.47, Z = 0.51, P = 0.61) between high-power versus conventional power ablation. The high-power group was fewer in acute PVs reconnections (P = 0.0001) , shorter in ablation time (P < 0.0001) , and the total procedural time (P < 0.0001) compared with conventional power group. Conclusion: High-power ablation of AF was safe and efficient compared with that of conventional power ablation, and reduced ablation time and the total procedural time.