Introduction: Utilizing a 3-dimensional (3-D) mapping system and intracardiac echocardiography (ICE) has allowed ablation procedures with less or without fluoroscopy; however, there is limited data for patients with cardiac electronic implantable device (CIED) leads regarding the suspected risk of lead injury. Therefore, we sought to explore technics to perform safe trans-septal approach and catheter manipulation technique in patients with CIED leads. Methods and Results: This study comprised 68 consecutive patients (45 [66.2%] males, median [interquartile range] 73 [68–77] years old) with CIED who underwent catheter ablation for supraventricular tachycardia, 16 without fluoroscopy (zero-fluoro group) and 52 with fluoroscopy (conventional-fluoro group), between July 2019 and April 2021. All procedures were performed under a 3-D mapping system and ICE guidance. We compared the differences in treatment and development of complications between the two groups. The procedures were mainly atrial fibrillation (73.6%) and atrial tachycardia. The median time from venipuncture to trans-septal procedure (zero-fluoro vs. conventional-fluoro group: 27.0 min vs. 23.5 min, P=0.71) and total procedure time (215 min vs. 172 min, P=0.55) were not different between the two groups. The acute procedural success rate (100% vs. 98.1%, P=1.00) and reduction of atrial high-rate episodes at 6 months (3.2 [0.3–93.9]% vs. 1.0 [0.0–14.9]%, P=0.33) did not differ between the two groups. No patient showed lead-related complications in both groups. Conclusions: Zero-fluoro ablation for supraventricular arrhythmia using 3-D mapping and ICE in patients with CIED leads was feasible under careful catheter manipulation.

Introduction: The sinoatrial node (SAN) should be identified before superior vena cava (SVC) isolation to avoid SAN injury. However, its location cannot be identified without restoring sinus rhythm. This study evaluated the usefulness of the anatomically defined SAN by comparing it with the electrically confirmed SAN (e-SAN) and aimed to establish a safe and more efficient anatomical reference for SVC isolation than the previously reported reference of the roof of the right superior pulmonary vein (RSPV roof). Methods and Results: The e-SAN was identified as the earliest activation site in the electro-anatomical map obtained during sinus rhythm. The anatomically defined SAN, the cranial edge of the crista terminalis (CT) visualized with intracardiac echocardiography (CT top), and the RSPV roof were tagged on one map. The distance from the e-SAN to each reference was measured. Among 81 patients, the height of the e-SAN from the CT top was −3.5 ± 10.3 mm. The e-SAN existed below 10 mm above the CT top in 78 (96%) patients and below the RSPV roof in 77 (95%) patients. A longer SVC sleeve was measured from 10 mm above the CT top compared to the RSPV roof (28.7 ± 11.2 vs. 22.5 ± 11.3 mm, p <0.001). Faster heart rate predicted an e-SAN location higher than the CT top (adjusted OR [95% CI]; per 10 bpm increase: 1.6 [1.15–2.22], p <0.01). Conclusion: The CT top is useful in predicting the upper limit of the e-SAN and can provide a useful reference for SVC isolation.