Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota; Department of Cardiovascular Medicine, Simone Veil Hospital, Cannes, France.
Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.
J Am Soc Echocardiogr. 2022 Feb;35(2):165-175. doi: 10.1016/j.echo.2021.09.004. Epub 2021 Sep 10.
The dynamic consequences of mitral annular disjunction (MAD) on the mitral apparatus and the left ventricle remain unclear and are crucial in the context of mitral surgery. Thus, the aim of this study was to assess mitral valvular, annular, and ventricular dynamics in mitral valve prolapse (MVP) stratified by presence of MAD.
In 61 patients (mean age, 62 ± 11 years; 25% women) with MVP and severe mitral regurgitation undergoing mitral surgery between 2009 and 2016, valvular and annular dimensions and dynamics by two-dimensional transthoracic and three-dimensional transesophageal echocardiography and left ventricular dimensions and dynamics were analyzed stratified by presence of MAD before and after surgery.
MAD (mean, 8 ± 3 mm) was diagnosed in 27 patients (44%; with a mean effective regurgitant orifice area of 0.55 ± 0.20 cm and similar to patients without MAD), more frequently in bileaflet prolapse (52% vs 18% in patients without MAD, P = .004), consistently involving P2 (P = .005). Patients with MAD displayed larger diastolic annular areas (mean, 1,646 ± 410 vs 1,380 ± 348 mm), circumferences (mean, 150 ± 19 vs 137 ± 16 mm), and intercommissural diameters (mean, 48 ± 7 vs 43 ± 6 mm) compared with those without MAD (P ≤ .008 for all). Dynamically, mid- and late systolic excess intercommissural diameter, annular area, and circumference enlargement were associated with MAD (P ≤ .01 for all). MAD was also associated with dynamically annular slippage, larger prolapse volume and height (P ≤ .007), and larger leaflet area (mean, 2,053 ± 620 vs 1,692 ± 488 mm, P = .01). Although patients with MAD compared with those without MAD showed similar ejection fractions (mean, 65 ± 5% vs 62 ± 8%, respectively, P = .10), systolic basal posterior thickness was increased in patients with MAD (mean, 19 ± 2 vs 15 ± 2 mm, P < .001), with higher systolic thickening of the basal posterior wall (mean, 74 ± 27% vs 50 ± 28%) and higher ratio of basal wall thickness to diameter (P ≤ .01 for both). However, after mitral repair, MAD disappeared, and LV diameter, wall thickness, and wall thickening showed no difference between patients with MAD and those without MAD (P ≥ .10 for all).
MAD in patients with MVP involves a predominant phenotype of bileaflet MVP and causes profound annular dynamic alterations with considerable expansion and excess annular enlargement in systole, potentially affecting leaflet coaptation. MAD myocardial and annular slippage simulates vigorous left ventricular function without true benefit after surgical annular suture. Thus, although MAD does not hinder the feasibility and quality of valve repair, it requires careful suture of ring to ventricular myocardium, lest it persist postoperatively.
二尖瓣环分离（MAD）对二尖瓣装置和左心室的动态影响尚不清楚，在二尖瓣手术中至关重要。因此，本研究旨在评估二尖瓣脱垂（MVP）患者中存在 MAD 时的二尖瓣瓣叶、瓣环和心室动力学。
2009 年至 2016 年间，61 例 MVP 伴严重二尖瓣反流患者接受二尖瓣手术，在术前和术后通过二维经胸超声心动图和三维经食管超声心动图评估瓣叶和瓣环的二维和三维结构和动力学，并分析存在 MAD 的患者的左心室结构和动力学。
27 例患者（44%）诊断为 MAD（平均 8±3mm），这些患者的平均有效反流口面积为 0.55±0.20cm，与无 MAD 的患者相似（MAD 组为 0.55±0.20cm，无 MAD 组为 0.55±0.20cm）。MAD 更常发生在双瓣叶脱垂患者中（52%比无 MAD 的患者中 18%，P=0.004），始终累及 P2（P=0.005）。与无 MAD 的患者相比，MAD 患者的舒张期瓣环面积（平均 1646±410 比 1380±348mm）、周长（平均 150±19 比 137±16mm）和瓣环间径（平均 48±7 比 43±6mm）更大（所有 P 值均≤0.008）。动态上，中晚期收缩期瓣环间径、瓣环面积和周长过度增大与 MAD 相关（所有 P 值均≤0.01）。MAD 还与瓣环动态滑动、更大的脱垂体积和高度（P 值均≤0.007）以及更大的瓣叶面积（平均 2053±620 比 1692±488mm，P=0.01）相关。尽管与无 MAD 的患者相比，MAD 患者的射血分数（平均 65±5%比 62±8%，P=0.10）相似，但 MAD 患者的收缩期基底部后厚度增加（平均 19±2 比 15±2mm，P<0.001），基底部后壁的收缩增厚程度更高（平均 74±27%比 50±28%），基底部壁厚度与直径的比值更高（所有 P 值均≤0.01）。然而，在二尖瓣修复后，MAD 消失，MAD 患者和无 MAD 患者的左心室直径、壁厚度和壁增厚无差异（所有 P 值均≥0.10）。
MVP 患者的 MAD 涉及双瓣叶 MVP 的主要表型，并导致明显的瓣环动态改变，在收缩期瓣环明显扩张和过度增大，可能影响瓣叶对合。MAD 心肌和瓣环滑动模拟了活跃的左心室功能，但在手术后并没有真正的获益。因此，尽管 MAD 不影响瓣环修复的可行性和质量，但需要仔细缝合环和心室心肌，以免术后持续存在。
