Background

The prevalence of isolated cleft mitral valve (MV; no concomitant congenital heart disease or degenerative MV disease) with significant mitral regurgitation (MR) diagnosed using two-dimensional echocardiography (2DE) has been reported to be very low. Three-dimensional echocardiography (3DE) has enabled a more comprehensive visualization of the MV and detailed understanding of the mechanisms of MR and can potentially reveal isolated cleft MV that is not recognized with 2DE. The aim of this study was to determine, using 3DE, the prevalence, location, and associated MV annular and left ventricular characteristics of isolated cleft MV, in the absence of associated congenital heart disease, in patients with significant MR.

Methods

A total of 1,092 patients with unexplained moderate or greater MR on two-dimensional transthoracic echocardiography who were referred for three-dimensional transesophageal echocardiography between 2005 and 2017 (n = 626) were retrospectively studied. Left ventricular dimensions and function were determined, and quantitative MR assessment and three-dimensional analysis of the MV annulus was performed.

Results

Twenty-one patients (prevalence 3.3%) were diagnosed with isolated cleft MV using three-dimensional transesophageal echocardiography but not 2DE. The majority of these patients (n = 16) were noted to have anterior cleft MVs, with most located in the mid-A1 (n = 10) or mid-A3 (n = 5) scallops. Posterior clefts were less common (n = 5) and occurred at the site of the natural scallop indentations (three between P1 and P2 and two between P2 and P3). Among patients with either anterior or posterior MV cleft, there were no differences in left ventricular ejection fraction or three-dimensional MV geometry (annular distance, height, circumference, and area). There was a trend toward worse MR severity in patients with anterior cleft MV.

Conclusions

In patients with otherwise unexplained significant MR referred for transesophageal echocardiography, 3DE uncovered a considerably higher prevalence of isolated cleft MV than previously reported by 2DE, with the majority located in the anterior MV. Although the annular geometry was similar between patients with anterior and posterior cleft MVs, a trend toward more severe MR in anterior clefts may reflect underlying abnormalities in the embryologic development of the anterior MV leaflet. Evaluation of MV pathology is improved by 3DE, which should be used routinely in the setting significant MR.

中文翻译：

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三维超声心动图诊断孤立性二尖瓣裂

背景

据报道，使用二维超声心动图（2DE）诊断为孤立性二尖瓣裂（MV；无伴发性先天性心脏病或退行性MV疾病）并伴有明显的二尖瓣关闭不全（MR）的患病率非常低。三维超声心动图（3DE）已使MV的可视化更加全面，并且对MR的机理有了更深入的了解，并有可能揭示2DE无法识别的孤立性2裂MV。这项研究的目的是在不伴有先天性心脏病的情况下，使用3DE来确定孤立性MV的患病率，位置以及相关的MV环形和左心室特征。

方法

 回顾性研究了2005年至2017年间接受二维三维经食管超声心动图检查的1,092例经二维经胸超声心动图检查无法解释的中度或更高MR的患者（n = 626）。确定左心室的尺寸和功能，并进行定量的MR评估和MV环的三维分析。

结果

使用三维经食管超声心动图检查诊断为单纯性left裂MV的患者21例（患病率为3.3％），但未使用2DE确诊。这些患者中的大多数（n  = 16）被发现患有前c裂MV，大多数位于A1中段（n  = 10）或A3中段（n  = 5）扇贝。后裂少见（n  = 5），发生在自然扇贝凹痕的部位（P1和P2之间有3个，P2和P3之间有2个）。在有前部或后部MV裂隙的患者中，左心室射血分数或三维MV几何形状（环形距离，高度，周长和面积）均无差异。前裂MV患者的MR严重程度有恶化的趋势。

结论

对于经食管超声心动图检查无法解释的明显MR的患者，3DE发现孤立的c裂MV的患病率比2DE先前报道的要高，大多数位于前部MV。尽管前裂和后裂MV患者的环形几何形状相似，但前裂MR向更严重MR的趋势可能反映了前MV小叶的胚胎发育中潜在的异常。3DE改善了MV病理学的评估，应在设置显着MR时常规使用。