Catheter Ablation of Focal Atrial Tachycardia with Early Activation Close to the His-Bundle from the Non Coronary Aortic Cusp

Abstract Background Atrial tachycardia (AT) ablation with earliest activation site close to the His-Bundle is a challenge due to the risk of complete AV block by its proximity to His-Purkinje system (HPS). An alternative to minimize this risk is to position the catheter on the non-coronary cusp (NCC), which is anatomically contiguous to the para-Hisian region. Objectives The aim of this study was to perform a literature review and evaluate the electrophysiological characteristics, safety, and success rate of catheter-based radiofrequency (RF) delivery in the NCC for the treatment of para-Hisian AT in a case series. Methods This study performed a retrospective evaluation of ten patients (Age: 36±10 y-o) who had been referred for SVT ablation and presented a diagnosis of para-Hisian focal AT confirmed by classical electrophysiological maneuvers. For statistical analysis, a p-value of <0.05 was considered statistically significant. Results The earliest atrial activation at the His position was 28±12ms from the P wave and at the NCC was 3±2ms earlier than His position, without evidence of His potential in all patients. RF was applied on the NCC (4-mm-tip catheter; 30W, 55ºC), and the tachycardia was interrupted in 5±3s with no increase in the PR interval or evidence of junctional rhythm. Electrophysiological tests did not reinduce tachycardia in 9/10 of patients. There were no complications in all procedures. During the 30 ± 12 months follow-up, no patient presented tachycardia recurrence. Conclusion The percutaneous treatment of para-Hisian AT through the NCC is an effective and safe strategy, which represents an interesting option for the treatment of this complex arrhythmia. (Arq Bras Cardiol. 2021; 116(1):119-126)

【摘要】背景：针对最早激动位点紧邻希氏束的房性心动过速（Atrial tachycardia, AT）实施消融治疗时，因操作区域毗邻希氏-浦肯野系统（His-Purkinje system, HPS），存在诱发完全性房室传导阻滞的风险，手术难度较高。降低此类风险的可行方案之一是将消融导管置于无冠状窦（non-coronary cusp, NCC），该解剖结构与希旁区存在解剖学毗邻关系。
研究目的：本研究旨在通过文献回顾结合一项病例系列研究，评估经无冠状窦行导管射频（radiofrequency, RF）消融治疗希旁区AT的电生理特征、安全性及手术成功率。
方法：本研究对10例因室上性心动过速（SVT）消融转诊、经经典电生理操作确诊为希旁局灶性AT的患者进行回顾性分析（年龄：36±10岁）。统计学分析以P值<0.05作为具有统计学意义的判定标准。
结果：希氏束区域的最早心房激动距离P波为28±12ms，无冠状窦区域的最早心房激动较希氏束区域提前3±2ms，所有患者均未记录到希氏电位。术中于无冠状窦处应用4mm顶端导管行射频消融（功率30W，温度上限55℃），心动过速于5±3s内终止，未出现PR间期延长或交界性心律表现。电生理检查显示，10例患者中有9例未再诱发心动过速。所有手术均未发生并发症。随访30±12个月期间，无患者出现心动过速复发。
结论：经皮经无冠状窦途径治疗希旁区AT是一种安全有效的策略，为该复杂性心律失常的治疗提供了极具潜力的可选方案。
(Arq Bras Cardiol. 2021; 116(1):119-126)