速度向量成像定量评价不同程度缺血心肌局部功能的研究

目的 应用速度向量成像(VVI)技术评价不同程度缺血心肌局部功能的变化.方法 50例冠心病患者,在VVI条件下经胸采集心尖四腔观、两腔观和长轴观超声心动图图像.根据冠状动脉(冠脉)造影结果将所有心肌节段分为5组:0级组,冠脉无狭窄;1级组,冠脉狭窄＜50%;2级组,冠脉狭窄50%～74%;3级组,冠脉狭窄75%～99%;4级组,冠脉完全闭塞.测量各组心肌节段收缩期应变(e)、应变率(SRs),舒张早期应变率(Sre)、舒张晚期应变率(Sra)及Sre/Sra.结果①与0级组比较,1级组Sre、Sre/Sra,2～4级组SRs、Sre、Sre/Sra,2级组和4级组ε均降低(P＜0.05);②1～4级组间比较,2级组ε、SRs、Sra低于1级组(P＜0.05),3级组ε、Sre、Sra高于2级组(P＜0.05),1级组与3级组比较差异无统计学意义;4级组ε、SRs、Sre低于1级组,Sre低于2级组,ε、SRs、Sre低于3级组(P＜0.05).结论随冠脉狭窄程度加重,缺血心肌早期先后出现舒张和收缩功能异常,并出现明显减低后回升再降低的双向变化.

Quantitative assessment of myocardial regional function of different coronary atherosclerosis severity using velocity vector imaging

Objective To assess isehemic myocardial regional function of different coronary atherosclerosis using velocity vector imaging(VVI).Methods Two-dimensional images of apical four-，two-chamber and long-axis view were obtained in 50 patients with coronary artery disease.All segments of the left ventricle were divided into 5 groups：group 0 with no coronary artery stenosis，group 1 with stenosis＜50%，group 2 with stenosis 50%to 74%，group 3 with stenosis 75%to 99%and group 4 with a completely occluded coronary artery.The segmental myocardial systolic peak strain(ε)，systolic strain rate(SRs)，early diastolic strain rate(SRe)，late diastolic strain rate(SRa)and their ratio(SRe/SRa)were analyzed with VVI offline software.Results①Compared with group 0，SRe and SRe/SRa of group 1，SRs，SRe，SRe/SRa of group 2～4，εof group 2 and group 4 decreased significantly(P＜0.05).②In the comparison of four ischemic groups，ε，SRe，SRa of group 3 were markedly higher than those of group 2，while ε，SRs，SRa of group 2 were lower than those of group 1(P＜0.05)；for group 4，ε，SRs，SRe were lower than those of group 1，SRe was lower than that of group 2，and ε，SRs，SRe were lower than those of group 3(P＜0.05).Conclusions In the process of coronary atherosclerosis，myocardial diastolic and systolic dysfunction occurred early and orderly，and has a bidirectional change：decreased firstly，then increased and decreased at last.