应变率成像技术对冠状动脉粥样硬化性心脏病患者左室局部舒张功能异常的评估

摘要

背景:局部心肌舒张功能异常是心肌缺血、梗死的早期和特征性表现.应变率成像是一种新型超声成像技术,具有良好的时间和空间分辨率,可用于定量分析局部心肌功能.目的:应用应变率成像技术定量分析并比较心绞痛与心肌梗死患者左室缺血及梗死心肌舒张期应变率变化,探讨其评价冠状动脉粥样硬化性心脏病(简称冠心病)患者左室局部舒张功能异常的价值.设计:病例对照研究.单位:中山大学附属第二医院心血管内科.对象:选取2005-10/2006-04中山大学附属第二医院门诊和住院患者作为研究对象,其中冠心病心绞痛组11例、心肌梗死组21例,对照组20例.方法:常规超声检查后,取心尖四腔、二腔及左室长轴观,应用二维彩色组织多普勒速度模式记录左室侧壁、后间隔、下壁、前壁、后壁及前间隔的运动图像,并存入磁光盘.利用QLAB4.2分析软件进行脱机分析,获取SR曲线.主要观察指标:分析心绞痛组缺血心肌、心肌梗死组梗死心肌和对照组左室心肌节段.分别测量舒张早期峰值应变率(SRe)和舒张晚期峰值应变率(SRa).结果:缺血、梗死心肌的SRe和SRa均显著低于正常心肌(P＜0.05);梗死心肌与缺血心肌相比,SRe及SRa均无显著性差异(P＞0.05).结论:应变率成像测得SRe和SRa可反映冠心病患者左室局部心肌舒张功能异常,但对于缺血与梗死心肌的鉴别诊断价值有限.%BACKGROUND:Regional myocardial diastolic dysfunction has been recognized as a sensitive and characteristic sign of myocardial ischemia and infarction,train rate imaging(SRI)is a novel ultrasonic technique with good spatial and high temporal resolution,nd it can be used to quantitatively analyze regional myocardial function.OBJECTIVE:To investigate the characteristics of the longitudinal diastolic strain rate(SR)in ischemic and infarct myocardium by SRI,n order to explore the clinical value of SRI in evaluating regional left ventricular diastolic dysfunction in patients with coronary artery disease.DESIGN:A case-control study.SETTING:Department of Cardiology.Second Affiliated Hospital of Sun Yat-Sen University.PARTICIPANTS:All the participants were selected from outpatients and/or inpatients of the Second Affiliated Hospital of Sun Yat-sen University between October 2005 and April 2006.Twenty-one patients with myocardial infarction(MI group)and 11 patients with angina pectoris(AP group)were enrolled in the study.Twenty age-matched healthy subjects served as controls.METHODS:After performing conventional echocardiographic examination,olor tissue Doppler images from apical four-,three- and two-chamber views (posterior septum and lateral wall,nterior septum and posterior wall,nterior and inferior wall)were recorded on magneto-optical disk.Then SR curves were derived from the stored images off-line using QLAB 4.2software.MAIN OUTCOME MEASURES:Ischemic segments in the AP group,nfarct segments in the MI group and normal segments in the control group were analyzed.The parameters measured included peak early diastolic SR (SRe)and peak late diastolic SR(SRa).RESULTS:Compared with the normal myocardium,oth SRe and SRa decreased significantly in the infarct and ischemic myocardium(all P＜0.05).No significant differences were observed with respect to SRe and SRa between the infarct and ischemic myocardium(both P＞0.05).CONCLUSION:SRI can be used to quantitatively analyze regional myocardial diastolic dysfunction in patients with coronary artery disease,ut its value is limited in differentiating infarct from ischemic myocardium.