多普勒频谱法评价早期糖尿病心肌病左室整体舒张功能的实验研究

目的　探讨利用多普勒频谱成像评价链尿佐 (STZ)诱导的兔糖尿病 (DM)模型早期糖尿病心肌病左室舒张功能障碍的价值 ,以及糖尿病心肌病左室舒张功能障碍的演变规律及发生机制。方法　应用传统多普勒法测定 DM兔二尖瓣口血流频谱 ,测定以下指标 :舒张早期峰值速度 (E) ,舒张晚期峰值速度 (A) ,以及 E/A值 ,E波减速时间 (EDT) ,等容舒张时间 (IVRT) ,计算快速充盈分数和室壁僵硬度 ,并同 10只正常组兔对照。结果　左室整体舒张功能的减退出现在模型复制成功后 4～ 8周不等 ,主要表现为 :从第 4周起 ,EDT明显缩短 ,左室壁僵硬度显著增加 ;从第 6周起 ,E、平均速度 (Em)显著降低 ,A在所有组中均无明显变化 ,E/A比值显著减小 ,E、A峰倒置 ,即 E/A<1;IVRT则自第 8周起显著延长。随时间推移 ,以上舒张功能损害有加重趋势。快速充盈分数在整个实验过程中无明显变化。结论　左室舒张功能障碍出现在模型成功复制后 4～ 8周 ,随病情发展加重。多普勒频谱成像能够发现早期的糖尿病心肌病左室舒张功能障碍

Experimental Study on Assessment of Left Ventricular Diastolic Function in Early Diabetic Cardiomyopathy Using Color Doppler Flow Imaging

Objective:To assess the value of color D op pler flow imaging-pulse Doppler(CDFI-PW)in diastole function of left ventric le in early diabetic cardiomyopathy.Methods:The flow of mitral ring was analysed.The parameters su ch as diastole early period velocity (Ea),diastole later period velocity (Aa) an d Ea/Aa were observed and compared with normal rabbits.Results:Diastolic dysfunction of left ventricle was found in STZ -induced diabetic rabbits detected by CDFI at the 4-8th week.The deceleration time of E wave (EDT)was shortened at the 4th week.The left ventricular wall rigi dity was increased significantly at the 4th week too.The peak and mean velocitie s of E wave and E/A were reduced notably.Isovolumic relaxation time(IVRT) was pro longed at the 8th week.Conclusions:The diastolic dysfunction in STZ-induced diabetic r abbits were impaired as early as at the 4-8th week and along with the severit y of the disease.CDFI-PW can assess early left ventriclular diastolic dysfuncti on in diabetic cardiomyopathy.