组织同步成像评价肝细胞生长因子治疗心肌梗死犬的左心室同步状况

Tissue synchronization imaging assessment of ventricular systolic asynchrony in myocardial infarction dogs with hepatocyte growth factor therapy

目的探讨组织同步成像(TSI)在评价肝细胞生长因子(HGF)治疗心肌梗死犬对心肌同步状况影响中的应用。方法将11只杂种犬随机分成HGF治疗组(6只)和对照组(5只),均结扎左冠状动脉前降支制成心肌梗死模型,在HGF组的梗死心肌周围注射HGF1ml,对照组的梗死心肌周围注射等量生理盐水,术后4、8周行超声心动图检查,检测心功能及左心室重构指标,采用组织同步成像(TSI)测量左心室心肌12节段的收缩期达峰值速度时间(Ts),并计算12节段Ts的标准差(Ts-SD)和Ts最大和最小时间的差值(Tsmax-min)。术后8周取心肌组织检测Ⅰ、Ⅲ型胶原含量并比较2组差异。结果术后8周与对照组相比,HGF组左心室收缩末容积(LVESV)小于对照组,左心室射血分数(LVEF)大于对照组(P<0.05)。对2组左心室壁各节段的Ts进行多因素方差分析显示,HGF组前间隔中段Ts在术后第4及8周均小于对照组(P<0.05)。术后8周对照组Ts-SD为(75.1±20.2)ms,HGF组为(38.7±6.4)ms(P<0.05);当分组因素和时间因素交互作用时,2组Tsmax-min比较差异有统计学意义(P=0.03)。术后8周HGF组Ⅲ型胶原含量高于对照组,Ⅰ型与Ⅲ型胶原含量比值低于对照组(P<0.05)。结论TSI可以检测心肌梗死犬心肌同步状况,采用HGF治疗后心肌同步性随着LVESV的减小和LVEF的增加而改善。

ObjectiveTissue synchronization imaging (TSI) was used to assess systolic asynchrony in myocardial infarction dogs and the improvement of synchronicity after hepatocyte growth factor (HGF) therapy. MethodsEleven dogs were randomly divided into two groups: HGF group and the control group. Dog models of ligated proximal left anterior descending coronary artery were used. HGF group was administrated with 1 ml HGF around the ischemic areas, and the control group was administrated with 0.9% of sodium chloride solution 1 ml. After LAD ligated 4 to 8 weeks, LVESV and LVEF were determined on 2D echocardiography. TSI studies were performed in each group. The regional times to systolic velocity peak (Ts) were measured in 12 segments. Standard deviations of Ts (Ts-SD) and difference of Ts (Ts max-min) of all 12 segments were computed. LV myocardium specimens were obtained and stained for histological examination to assess the collagen content. ResultsCompared with the control group, LVESV was significantly decreased in HGF group, and it tended to decrease more with time prolonged. LVEF was significantly increased in HGF group as compared with the controls, and it tended to improve more with time prolonged. Ts in the middle interventriclar septum in HGF group was significant shorter than in the control group. Ts-SD was prolonged in the controls compared with HGF group (8 week: 75.1±20.2 ms vs 38.7±6.4 ms, P<0.05). When considering group and time factors, Ts max-min between controls and HGF group was different. In HGF-group, compared with the control, high type of collagen Ⅲ volume and low Ⅰ/Ⅲ ratio existed (P<0.05). ConclusionsTSI is useful for assessing the synchronicity in MI dogs, and after therapy, systolic synchronicity tends to be shorten along with increasing LVESV and improving LVEF.