犬急性缺血心肌非同步运动与左心功能的相关性研究

Relative study on ventricular asynchrony and left ventricular function in experimental acute myocardial ischemia of canines

目的:探讨定量组织速度成像(QTVI)评价犬急性缺血心肌非同步运动与左心功能的相关性。方法:健康犬21只,暴露心脏,于左冠状动脉主干阻断前(对照组)、后(实验组)分别获取左心室12个节段的QTVI曲线,测量各点QRS波起点至心肌收缩期峰值速度和舒张早期峰值速度的时间(Ts和Te),计算同一壁内3个节段Ts最大差值(Intra-△Ts)和Te最大差值(In-tra-△Te)以及左心室12个节段Ts和Te的最大差值(Max-△Ts和Max-△Te)。心室间的不同步指标测量QRS波起点到主动脉瓣血流频谱起点时间(Q-A),QRS波起点到肺动脉瓣血流频谱起点时间(Q-P)及其差值(Q-AP)。左室射血分数(LVEF)和Tei指数反映左心整体功能。结果:实验组缺血节段Intra-△Ts、Intra-△Te、Max-△Ts、Max-△Te、Q-A、Q-P及Q-AP较对照组明显延长(P<0.01),Max-△Ts与Tei指数呈正相关(P<0.05),与LVEF呈负相关(P<0.05)。QRS与Max-△Te呈正相关(P<0.05)。结论:犬急性缺血左心室内及心室间心肌存在明显非同步运动,且与心功能密切相关。

Objective： To evaluate the relationship between ventrieular asynchrony and left ventricular function in acute myocardial ischemia of canines. Quantitative tissue velocity imaging（QTVI） was used. Methods： Twenty-one canines were studied on QTVI, left coronary artery （LCA） was carefully dissected and occluded. Before LCA occlusion, the canines were defined as the normal contrul group and after occlusion defined as the experimental group. The regional velocity profiles in 12 segments of left ventricle （LV） were obtained. The time from onset of QRS to peak velocity during systole and early diastole（Ts and Te） were measured. The maximal difference in Ts and Te within the same wall （Intra-△Ts and Intra-△Te） and all 12 segments（Max-△Ts and Max-△Te） of the LV were calculated. The time from onset of QRS to beginning time of flow velocity spectra in aortic valve （Q-A） and pulmonary value （Q-P） and their differences （Q-AP） were measured. The parameters of LV pump function include the left ventricular ejection fraction （LVEF） and Tel index were calculated. Results： Intra-△Ts, Intra- △Te, Max-△Ts, Max-△Te, Q-A, Q-P and Q-AP were significantly prolonged compared with the control group. Max-△Ts was positively correlated with Tel index （P〈0.05） and negatively with LVEF （P〈0.05）, Max-△Te was positively correlated with QRS duration（P〈0.05）. Conclusions： The inter- and intraventrieular asynchrony exists in canines with acute left ventrieular ischemia and it has relation with LV function.