小剂量多巴酚丁胺负荷评价缺血性二尖瓣反流患者二尖瓣复合结构变化特点的超声研究

A quantitative study of mitral annulus dynamics in ischemic mitral regurgitation by transesophageal 3-dimensional echocardiography with low-dose dobutamine

目的采用经食管三维超声心动图(RT 3D-TEE)技术结合小剂量多巴酚丁胺,分析缺血性二尖瓣反流患者和正常对照者的二尖瓣几何形态学参数在静息及负荷状态时的变化特点。方法采用MVQ技术对25例缺血性心二尖瓣反流组患者及20名正常对照者组进行检查,应用MVQ软件测量并分析对照组及缺血性二尖瓣反流组患者在静息及使用小剂量多巴酚丁胺后二尖瓣环及瓣叶几何形态学参数变化特点。结果正常对照组二尖瓣环及瓣叶结构相对稳定,并不随小剂量多巴酚丁胺的使用而发生明显变化;对缺血性二尖瓣反流组患者使用多巴酚丁胺,二尖瓣环及瓣叶空间结构变化主要体现在瓣环结构的构型变化及由其产生的二尖瓣瓣叶对合参数的变化;小剂量多巴酚丁胺的使用后二尖瓣环构型相对朝向正常"鞍状"结构的回归。结论小剂量负荷时缺血性二尖瓣反流程度的减少依赖于左心功能相对增加后二尖瓣环构型相对朝向正常"鞍状"结构的回归,二尖瓣的帆状穹窿构型变化在保证二尖瓣环及瓣叶结构稳定性中起着至关重要的作用。

Objective To investigate the clinical value of mitral valve quantitative （MVQ） software selecting the significant parameters in diagnosing ischemic mitral regurgitation （IMR） and analyze the mechanism of mural valve regurgitation by MVQ in clinical. Methods Real-time three-dimensional transesophageal echocardiography （RT 3D-TEE） was performed on forty-five patients, in which 25 patients with ischemic mitral regurgitation, another 20 patients without mural valve regurgitation regarded as control group. The images were stored and processed with MVQ soft ware off line. Parameters of mural valve structure were measured in mitral valve 3D mode. Results The results showed the normal subjects tends to keep the relative stable structure and geometry on mitral-leaflets and annular both at the rest condition and dobutamine infusion. Conclusion The structure and geometry of mitral-leaftets and annular in patients with obvious IMR would change especial on the annular structure and leaflets competence; It would cause the regression towards the saddle structure with low-dose dobutamine.