【作者】 李隽；

【导师】 朱文玲； 方理刚；

【作者基本信息】 中国协和医科大学 ， 临床医学， 2008， 博士

【摘要】 背景:冠心病心肌梗死患者左室功能异常常是由可逆性心肌损害和非可逆性心肌损害导致。通过冠状动脉血运重建术可使存活心肌的血流灌注和心室功能得以改善,从而改善患者的预后和生活质量,而不可逆心肌损害却不能从中受益。对缺血区心肌存活性的判别对冠心病的治疗决策、危险程度分级、疗效评价以及预后评估均有重要意义。临床常用的检测方法有正电子发射断层成像（PET）,双核素心肌显像（DISA）,小剂量多巴酚丁胺负荷超声心动试验（LDDSE）,核磁共振等。其中PET被认为是金标准。近年国外初步研究发现小剂量腺苷负荷超声心动图（LDASE）对探测存活心肌有较高的敏感性和特异性,且安全可行。目的:比较小剂量腺苷负荷超声心动图试验（LDASE）与⁹⁹mTc-甲氧基异丁腈（MIBI）/¹⁸F-脱氧葡萄糖（FDG）双核素同时采集法（DISA）单光子发射断层显像（SPECT）对急性心肌梗死患者早期存活心肌检出的准确性和安全性。方法:对36例急性心肌梗死患者与发病后2周内完成LDASE与DISA-SPECT。两种方法均按照17节段半定量法分析图像。心肌梗死后2—3个月随访二维心脏彩超超声心动图,以局部室壁运动改善作为心肌存活的金标准,比较两种方法检测存活心肌的敏感性和特异性,及安全性。结果:腺苷不良反应总发生率较高（14/36,38.9%）,但症状轻微,停药1～5min内自行缓解。与用药前比较,随腺苷剂量增加心率轻度增快（P=0.037）,血压略下降（无统计学意义）。心脏收缩功能改善,即左室收缩末期容积（LVESV）降低及射血分数（EF）升高（P值分别为0.002和0.0001）。LDASE检出存活心肌敏感性为90.3%,特异性为80.8%,阳性预测值与阴性预测值分别为84.8%和87.5%,准确性为85.9%。DISA-SPECT检出存活心肌敏感性81.2%,特异性78.3%,阳性预测值81.1%,阴性预测值83.1%,准确性80.2%。两种方法对运动异常节段（运动减弱或无运动或矛盾运动节段）存活心肌检出一致性为72.6%,无统计学差异。结论:LDASE对血流动力学影响小,可增强心肌收缩力及左室收缩功能。对急性心肌梗死后患者,LDASE与DISA-SPECT均能较敏感且准确地检出检出存活心肌,且无明显差异。LDASE腺苷剂量100μg/kg/min时敏感性和特异性较高,且不良反应小,可考虑为推荐剂量。更多还原

【Abstract】 Background The detection of reversible myocardial dysfunction has clinical and prognostic significance, as recent studies have suggested that dysfunctional but viable segments may recover after revascularization, which could do no good for those without viable myocardium. Technologies commonly used in clinical practice includes 18-flurodeoxy-glucose positron emission tomography(PET), dual-isotope emission simultaneous myocardial perfusion acquisition(DISA), low doses dobutamine stress echocardiography(LDDSE), magnetic resonance imaging (MRI), et al.Resently,low doses adenosine stress echocardiography (LDDSE) was reported successfully introduced as a cost-effective method with comparable diagnostic potential in detecting myocardial viability.Objective To compare the value of low-dose adenosine stress echocardiography (LDASE) and dual-isotope emission simultaneous myocardial perfusion acquisition ( technetium-99-m-tetrofosmin/ flurine 18-flurodeoxy-glucose ) single-photon emission computed tomography ( DISA-SPECT ) for myocardial viability assessment in patient with acute myocardial infarction .Methods LDASE and DISA-SPECT were pereformed in 36 patients within 2 weeks after onset of first acute MI. Furthermore, at 2-3 months after acute myocardial infarction, a follow-up echocardiography was taken. A 17-segment semi-quantitative scoring model was adopted for both techniques. Wall motion improvement at follow-up compared with baseline before adenosine infusion derived from two dimensional images was used as gold criteria for myocardial viability.Results This study has found a high rate of adverse events. However, most of them were mild and transcient, which could be relieved by ceasing the infusion within 1-5mins. Compared with baseline level, with the increment of adenosine dosage, heart rate increased mildly (P=0. 037), blood pressure decreased slightly(without statistical significance); left ventricularcontractile performance was improved, ie. left ventricularend-diastolicvolume(LVESV)decreased and left ventricular ejection fraction(LVEF) increased (P value were 0.002 and 0. 0001 respectively). The sensitivity,specificity, diagnostic accuracy, positive and nagetive predictive valuefor identification of viable myocardium were 90. 3%, 80. 8%, 85.9%, 84.8%和87.5%, respectively by LDASE and81.2%, 78.3%, 81.1%, 83.1%, 80.2%,respectively by DISA-SPECT. No difference was found between LDASE andDISA-SPECT for identifying viable myocardium in hypokinetic or akineticsegment.Conclusion Adenosine could slightly increase heart rates and reduce bloodpressure, but posed no risk on hemodynamic stability. It also significantlyincreases cardiac contractile force .Sensitivity and specificity were bothhigh by LDSAE and DISA for detecting viable myocardium in AMI patients withno difference. LDASE was sensitive and specific at 100ug/kg/min adenosineinfusion with minimal adverse effect. This dosage could be recommended forfurther study.更多还原