多普勒组织成像评价早期糖尿病心肌病患者左室功能的变化

背景与糖尿病肾病、糖尿病视网膜病变等其他并发症相比,糖尿病心肌病提出较晚,研究不够深入,发病隐匿,早期诊断方法不够完善,临床重视程度不够.目的利用多普勒组织成像评价糖尿病心肌病左室功能障碍特点.设计完全随机分组设计,对照实验.单位解放军成都军区总医院超声科.材料实验于2002-03/06在解放军成都军区总医院超声科完成.选用健康新西兰大白兔56只,雌雄不拘.方法①随机于56只实验兔中抽出10只作为对照组(不造成糖尿病模型),其余46只进行糖尿病模型复制(家兔禁食18 h,按65 mL/kg耳缘静脉一次注射链脲佐菌素溶液.将造模成功40只兔随机分成4组,即造模后2,4,6,8周组,每组10只.②采用全身数字化超声心动图仪检查造模后2,4,6,8周及对照组兔心脏二尖瓣环处室壁运动频谱.超声检测指标收缩期峰速度、射血前时间、局部射血时间、二尖瓣环4个不同部位平均收缩速度值、舒张早期速度、舒张晚期速度以及两者比值.③采用单因素方差分析进行组间差异比较.主要观察指标各组兔二尖瓣环后间隔和侧壁处的多普勒组织成像指标比较.结果纳入兔56只,造模失败6只,进入结果分析50只.糖尿病心肌病收缩功能障碍出现在模型成功复制6周,表现为后间隔和侧壁收缩期峰速度显著降低(P＜0.05),二尖瓣环水平4个不同部位平均收缩速度值减小(P＜0.05).造模后8周组兔后间隔处射血前时间明显长于对照组和造模后2周组(P＜0.05),侧壁处局部射血时间明显长于对照组、造模后2周组及造模后4周组(P＜0.05).从而导致左室壁收缩的不同步.左室舒张功能障碍出现在模型成功复制后4周,随实验时间延长而加重,表现为二尖瓣环后间隔和侧壁处的舒张早期速度逐渐减低(P＜0.05),舒张早期速度/舒张晚期速度显著减小(P＜0.05).结论①糖尿病心肌病左室舒张功能障碍以舒张早期峰速度降低、舒张早期速度/舒张晚期速度减小为特点.②糖尿病心肌病收缩功能障碍以局部组织收缩速度降低,部分节段射血前时间的延长以及部分节段射血时间延长为特点.

Assessment of left ventricle function in early diabetic cardiomyopathy by Doppler tissue imaging

BACKGROUND: Comparing with diabetic nephropathy and diabetic retinopathy, diabetic cardiomyopathy is put forward exceeded later and the research about it was not enough. It is difficult to detect diabetic cardiomyopathy in the earlier period so that it has usually been neglected.OBJECTIVE: To evaluate features of dysfunction of left ventricle in early diabetic cardiomyopathy by Doppler tissue imaging.DESIGN: Completely randomized and controlled experiment.SETTING: Ultrasound Department of General Hospital of Chengdu Military Area Command of Chinese PLA.MATERIALS: The experiment was carried out at Ultrasound Department of General Hospital of Chengdu Military Area Command of Chinese PLA from March to June 2002. Totally 56 New Zealand rabbits of either gender were selected.METHODS: ① Ten New Zealand rabbits was pulled out randomly from 56 as control group. The rest of 46 New Zealand rabbits were replicated diabetes mellitus by Streptozotocin (STZ), rabbits were absolute diet 18 hours and injected intravenously to ear marginal vein with 65 mg/kg of STZ. Then these rabbits were randomly divided into 4 groups as 2, 4, 6, 8th experimental group, with 10 rabbits in each group. ② Digit ultrasonic cardiogram equipment was used to examined interventricular motion of mitral annulus at 2nd,4th, 6th and 8th week in model groups and comparison group. The parameters such as systolic peak velocity (Sa), preejection period (PEP), local ejection time (ET), systolic mean velocity (Vm) of four various portions in mitral annulus and diastole early period velocity (Ea), diastole later period velocity (Aa), Ea/Aa were determined. ③ SPSS 11.0 was used for statistical analysis,one-factor analysis was adopted to compare difference of groups.MAIN OUTCOME MEASURES: The motion of lateral wall and posterior interventricular septum at mitral annulus were estimated by PW-DTI.RESULTS: Among 56 rabbits, 50 entered the final analysis and other 6 were lost because of failure modeling. Diastole dysfunction of left ventricle was discovered in STZ-inducod diabetic rabbits detected by tissue Doppler imaging at the 4th week. It showed that not only the tite of early period of diastole peak velocity (Ea) in mitral ring lateral wall and post-interval of left ventricle was reduced, but also the tite of Ea/Aa was reduced notably (P ＜ 0.05). Systolic dysfunction of left ventricle was discovered in STZ-in-duced diabetic rabbits detected by tissue Doppler imaging at the 6th week.It showed that local contraction peak velocity (Sa) of lateral wall and postseptum of mitral ring was decreased strikingly (P ＜ 0.05). Mean systole velocity of four various parts of mitral ring (Vm) was reduced at the 6th week (P ＜ 0.05). Pre-ejection period time (PEP) at post-septum and ejection time (ET) was elongated at lateral wall at the 8th week (P ＜ 0.05).CONCLUSION: ① Diastolic dysfunction of left ventricle is characterized by decrease of early period of diastole peak velocity and the tite of Ea/Aa.② Systolic dysfunction of diabetic cardiomyopathy is characterized by decrease of local contraction peak velocity and elongation of pre-ejection period time and ejection time.