Hôpital Cardiologique du Haut-Lévêque, CHU Bordeaux, L'Institut de RYthmologie et modélisation Cardiaque (LIRYC), Université Bordeaux, Bordeaux, France.
Hôpital Cardiologique du Haut-Lévêque, CHU Bordeaux, L'Institut de RYthmologie et modélisation Cardiaque (LIRYC), Université Bordeaux, Bordeaux, France.
Heart Rhythm. 2021 Mar;18(3):349-357. doi: 10.1016/j.hrthm.2020.11.008. Epub 2020 Nov 11.
Gaps in the roof line have been ascribed to epicardial conduction using the septopulmonary bundle.
We sought to evaluate the frequency of septopulmonary bundle bypass during roof line ablation, to describe anatomical conditions favoring this epicardial gap, and to propose an alternative strategy when present.
One hundred consecutive patients underwent atrial fibrillation ablation. A de novo roof line was created between the superior pulmonary veins. In cases of residual gaps, a floor line was created between the inferior pulmonary veins. Microtomography imaging and histological analyses of 5 human donor hearts were performed: a specific focus was made on the dome and the posterior wall.
Residual gaps were more frequent in roof lines than floor lines (33% vs 15%; P = .049). Electrogram morphologies, activation sequences, and pacing maneuvers indicated an epicardial bypass of the roof line in all cases. Conduction block was obtained in 67 roof lines and 28 floor lines, resulting in a 95% success rate of linear block, without "box" isolation. Between the superior pulmonary veins, the atrial myocardium was thicker and consistently displayed adipose tissue separating the septopulmonary bundle from the septoatrial bundle.
Epicardial conduction across the roof line is common and requires careful electrogram analysis to detect. In such cases, a floor line can be an effective alternative strategy, with clear validation criteria. Myocardial thickness and fat interposition may explain difficulties in achieving lesion transmurality during roof line ablation.
人们认为，心外膜传导是通过隔肺动脉束导致房顶线出现缝隙的。
我们旨在评估房顶线消融时隔肺动脉束旁路的发生频率，描述有利于这种心外膜缝隙出现的解剖条件，并在出现这种缝隙时提出一种替代策略。
连续 100 例房颤患者接受了房颤消融术。在肺静脉上方创建了一条新的房顶线。如果仍存在缝隙，则在肺静脉下方创建一条底线。对 5 个人体供心进行断层扫描成像和组织学分析：特别关注心穹窿和后壁。
房顶线的缝隙比底线更常见（33% vs 15%；P =.049）。电图形态、激活序列和起搏操作均表明所有病例均存在房顶线的心外膜旁路。在 67 条房顶线和 28 条底线中获得了传导阻滞，线性阻滞的成功率为 95%，无需“盒式”隔离。在肺静脉上方，心房心肌较厚，始终有脂肪组织将隔肺动脉束与房间隔束隔开。
房顶线的心外膜传导很常见，需要仔细的电图分析来检测。在这种情况下，底线可以作为一种有效的替代策略，具有明确的验证标准。心肌厚度和脂肪介入可能解释了在房顶线消融时难以实现透壁性损伤的原因。
