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.

We describe our use of intracardiac echocardiography (ICE) to guide endomyocardial biopsy of the left ventricle in a patient with chronic heart failure secondary to endocardial fibroelastosis. Under ICE guidance, we advanced the bioptome through the middle of the mitral annulus, within a trans-septal sheath, and guided the bioptome to the correct location on the mid-posterior wall of the left ventricle. This was performed without adverse events, such as injury to the chordae tendineae or mitral valve regurgitation. Therefore, ICE-guidance is possible for left-sided heart procedures and could lower the risk of complications and improve the biopsy rate for diagnosis.

Introduction: There are few reports of the characteristics, mechanisms, and outcomes of atrial tachycardia (AT) and atrial fibrillation (AF) ablation after cardiac surgery and concomitant Maze procedures. This study investigated the mechanisms and long-term outcomes of AT and AF ablation after various Maze procedures, especially we examined in detail whether the arrhythmia after Maze procedure was due to gap or not. Methods and Results: We analyzed 37 consecutive cases with AT and AF after cardiac surgery and Maze procedure between 2007 and 2019. Fifty-nine atrial arrythmias were induced in 37 consecutive cases, and 49 of those atrial arrythmias were mappable ATs. Forty-two ATs was related to the Maze procedure in the 49 mappable ATs (87.5%). All 37 consecutive cases had residual electrical conductions (gaps) in the Maze lines (88 gaps; 2.4±1.2 gaps/patient). Forty-two of 88 gaps (47.7%) were associated with gap-related ATs. The most common gap-related ATs in this study were peri-mitral atrial flutter in 22 cases. The median follow-up period after ablation was 3.6±3.2 years (median, 2.1 years; interquartile range, 0.89-6.84). The Kaplan-Meier analysis of freedom from recurrent atrial arrhythmia after Maze procedure was 79.9% at 1-year follow up and 69.3% at 4-year follow up. Conclusions: Reentry was the main mechanism of AT after cardiac surgery and concomitant various Maze procedures, and AT were largely related to the gap in the Maze line between mitral valve anulus and pulmonary vein isolation line. Catheter ablation of AT after various Maze procedures seemed to be effective and safe during long-term follow-up.