Carmo Pedro, Andrade Maria J, Aguiar Carlos, Rodrigues Rui, Gouveia Raquel, Silva José A
Cardiology Department, Hospital de Santa Cruz, Avenida Prof, Reinaldo dos Santos, 2790-134 Carnaxide, Portugal.
Cardiovasc Ultrasound. 2010 Dec 9;8:53. doi: 10.1186/1476-7120-8-53.
Mitral annular disjunction (MAD) consists of an altered spatial relation between the left atrial wall, the attachment of the mitral leaflets, and the top of the left ventricular (LV) free wall, manifested as a wide separation between the atrial wall-mitral valve junction and the top of the LV free wall. Originally described in association with myxomatous mitral valve disease, this abnormality was recently revisited by a surgical group that pointed its relevance for mitral valve reparability. The aims of this study were to investigate the echocardiographic prevalence of mitral annular disjunction in patients with myxomatous mitral valve disease, and to characterize the clinical profile and echocardiographic features of these patients.
We evaluated 38 patients with myxomatous mitral valve disease (mean age 57 ± 15 years; 18 females) and used standard transthoracic echocardiography for measuring the MAD. Mitral annular function, assessed by end-diastolic and end-systolic annular diameters, was compared between patients with and without MAD. We compared the incidence of arrhythmias in a subset of 21 patients studied with 24-hour Holter monitoring.
MAD was present in 21 (55%) patients (mean length: 7.4 ± 8.7 mm), and was more common in women (61% vs 38% in men; p = 0.047). MAD patients more frequently presented chest pain (43% vs 12% in the absence of MAD; p = 0.07). Mitral annular function was significantly impaired in patients with MAD in whom the mitral annular diameter was paradoxically larger in systole than in diastole: the diastolic-to-systolic mitral annular diameter difference was -4,6 ± 4,7 mm in these patients vs 3,4 ± 1,1 mm in those without MAD (p < 0.001). The severity of MAD significantly correlated with the occurrence of non-sustained ventricular tachycardia (NSVT) on Holter monitoring: MAD›8.5 mm was a strong predictor for (NSVT), (area under ROC curve = 0.74 (95% CI, 0.5-0.9); sensitivity 67%, specificity 83%). There were no differences between groups regarding functional class, severity of mitral regurgitation, LV volumes, and LV systolic function.
MAD is a common finding in myxomatous mitral valve disease patients, easily recognizable by transthoracic echocardiography. It is more prevalent in women and often associated with chest pain. MAD significantly disturbs mitral annular function and when severe predicts the occurrence of NSVT.
二尖瓣环分离（MAD）表现为左心房壁、二尖瓣叶附着处与左心室（LV）游离壁顶部之间空间关系的改变，表现为心房壁 - 二尖瓣交界处与LV游离壁顶部之间的广泛分离。最初是在黏液瘤样二尖瓣疾病中描述的，最近一个外科小组重新审视了这种异常情况，并指出其与二尖瓣修复的相关性。本研究的目的是调查黏液瘤样二尖瓣疾病患者中二尖瓣环分离的超声心动图患病率，并描述这些患者的临床特征和超声心动图特征。
我们评估了38例黏液瘤样二尖瓣疾病患者（平均年龄57±15岁；18名女性），并使用标准经胸超声心动图测量MAD。通过舒张末期和收缩末期环直径评估二尖瓣环功能，比较有和没有MAD的患者。我们比较了21例接受24小时动态心电图监测的患者亚组中的心律失常发生率。
21例（55%）患者存在MAD（平均长度：7.4±8.7mm），在女性中更常见（61%对男性中的38%；p = 0.047）。MAD患者更常出现胸痛（43%对无MAD患者中的12%；p = 0.07）。MAD患者的二尖瓣环功能明显受损，其中二尖瓣环直径在收缩期比舒张期反常地更大：这些患者的舒张期至收缩期二尖瓣环直径差为 -4.6±4.7mm，而无MAD患者为3.4±1.1mm（p < 0.001）。MAD的严重程度与动态心电图监测中室性非持续性心动过速（NSVT）的发生显著相关：MAD›8.5mm是NSVT的有力预测指标（ROC曲线下面积 = 0.74（95%CI，0.5 - 0.9）；敏感性67%，特异性83%）。在功能分级、二尖瓣反流严重程度、LV容积和LV收缩功能方面，两组之间没有差异。
MAD在黏液瘤样二尖瓣疾病患者中是常见发现，通过经胸超声心动图易于识别。它在女性中更普遍，且常与胸痛相关。MAD显著干扰二尖瓣环功能，严重时可预测NSVT的发生。
