Unité d'Électrophysiologie Cardiaque, Hôpital Cardiologique du Haut-Lévêque, CHU Bordeaux, L'Institut de Rythmologie et Modélisation Cardiaque (LIRYC), University of Bordeaux, Bordeaux, France.
Unité d'Électrophysiologie Cardiaque, Hôpital Cardiologique du Haut-Lévêque, CHU Bordeaux, L'Institut de Rythmologie et Modélisation Cardiaque (LIRYC), University of Bordeaux, Bordeaux, France.
Heart Rhythm. 2021 Nov;18(11):1951-1958. doi: 10.1016/j.hrthm.2021.06.1202. Epub 2021 Jul 1.
Mitral isthmus gaps have been ascribed to an epicardial musculature anatomically related to the great cardiac vein (GCV) and the vein of Marshall (VOM). Their lumen offers an access for radiofrequency application or ethanol infusion, respectively.
The purpose of this study was to evaluate the frequency of mitral isthmus gaps accessible via the GCV lumen, to assess their location around the GCV circumference, and to propose an efficient ablation strategy when present.
One hundred consecutive patients underwent VOM ethanol infusion (step 1) and endocardial linear ablation from the mitral annulus to the left inferior pulmonary vein (step 2). In cases of mitral isthmus gap, endovascular ablation of the GCV anchored wall facing the left atrium was systematically performed (step 3), while the opposite GCV free wall was targeted in case of block failure only (step 4).
After VOM ethanol infusion and endocardial ablation, mitral isthmus block occurred in 51 patients (51%). Pacing maneuvers and activation sequences demonstrated an epicardial gap via the VOM in 2 patients (2%) and via the GCV in 47 patients (47%). In the latter case, block was achieved at the GCV anchored wall in 42 patients (89%) and the GCV free wall in 5 patients (11%). Global success rate of mitral isthmus block was 98%. No tamponade occurred.
With the advent of VOM ethanol infusion, residual mitral isthmus gaps are mostly eliminated within the first centimeter of the GCV. Thorough mapping of the entire circumference of the GCV wall can help identify these epicardial gaps.
二尖瓣峡部间隙归因于解剖上与大冠状静脉（GCV）和Marshall 静脉（VOM）相关的心外膜肌肉。它们的管腔提供了射频应用或乙醇输注的通道。
本研究旨在评估通过 GCV 管腔可到达的二尖瓣峡部间隙的频率，评估它们在 GCV 圆周周围的位置，并在存在时提出有效的消融策略。
连续 100 例患者接受 VOM 乙醇输注（步骤 1）和从二尖瓣环到左下肺静脉的心内膜线性消融（步骤 2）。在存在二尖瓣峡部间隙的情况下，系统地对面向左心房的 GCV 锚定壁进行血管内消融（步骤 3），而仅在阻滞失败的情况下对相反的 GCV 游离壁进行消融（步骤 4）。
VOM 乙醇输注和心内膜消融后，51 例患者（51%）发生二尖瓣峡部阻滞。起搏操作和激活序列显示 2 例患者通过 VOM 出现心外膜间隙（2%），47 例患者通过 GCV 出现心外膜间隙（47%）。在后一种情况下，42 例患者（89%）在 GCV 锚定壁和 5 例患者（11%）在 GCV 游离壁实现阻滞。二尖瓣峡部阻滞的总体成功率为 98%。未发生心脏压塞。
随着 VOM 乙醇输注的出现，残余的二尖瓣峡部间隙大多在 GCV 的前 1 厘米内消除。对 GCV 壁整个圆周的彻底映射有助于识别这些心外膜间隙。
