小剂量多巴酚丁胺负荷超声心动图对二尖瓣反流左室舒张功能的研究

Study of left ventricular diastolic function in patients with mitral regurgitation by low dose dobutamine stress echocardiography

目的 探讨超声心动图评价二尖瓣反流左室舒张功能的可靠性方法。方法 应用小剂量多巴酚丁胺负荷超声心动图 (LDDSE)对 5 0例二尖瓣反流 (MR)患者进行了研究 ,其中包括 2 3例二尖瓣病变患者 (A组 )和 2 7例扩张型或缺血性心肌病患者 (B组 )。结果 A组左室压力最大下降速率 ( -dp/dtmax)和舒张期最大充盈速率 (PFR)显著高于B组 ,左室心肌松弛时间常数 (T )显著短于B组的测值 (P均 <0 .0 1) ;给于多巴酚丁胺 5 μg/(kg·min)后 ,两组 -dp/dtmax均显著增加 ( P 均 <0 .0 5 )。在B组中 ,应用LDDSE后 ,PFR增加 ,T缩短 (P均 <0 .0 0 1) ;E波峰值和E/A比值减少 (P <0 .0 0 1) ,舒张早期充盈容量指数 (EDFVI)和舒张早期与晚期充盈容量比值 (EDFV/LDFV)均显著增加 (P <0 .0 1) ,肺静脉血流Ar波减低 (P <0 .0 5 )至正常。结论 在扩张型或缺血性心肌病合并MR患者 ,左室舒张功能可存在异常 ,多巴酚丁胺能够改善这部分患者的左室舒张功能。

Objective To study the reliable methods of assessing the left ventricular diastolic funtion in patients with chronic mitral regurgitation(MR).Methods Low dose dobutamine stress echocardiography(LDDSE) were performed in 50 cases with MR,which included 23 cases with mitral valve diseases(group A) and 27 cases with dilated or ischemic cardiomyopathy(group B).Results ① There were higher negative maximal first derivation of left ventricular pressure(-dp/dt max ),peak filling rate(PFR) and lower time constant of left ventricular isovolumetric relaxation(T) in group A than those in group B;② Dobutamine significantly increased -dp/dt max in both groups;③ In group B dobutamine in induced an increase in PFR,early diastolic filling volume index(EDFVI),and the ratio of early to late filling volume (EDFV/LDFV),and a decrease in T and E wave velocity and E/A ratio,peak reversal velocity at atrial contraction(Ar) in pulmonary venous flow was also reduced(P< 0.05 ).Conclusions Left ventricular relaxation and distensibility are impaired in dilated or ischemic cardiomyopathy with MR and the impaired left ventricle diastolic function may be improved by dobutamine.