小剂量多巴酚丁胺超声心动图评价急性心肌梗死存活心肌的研究

Study of myocardial viability with acute myocardial infarction by low dose dobut amine stress echocardiography

目的 探讨梗死相关血管重建后存活心肌的功能恢复与左室重塑进程和左室功能恢复的关系。方法 将心肌梗死区异常室壁运动节段中存活心肌的节段数做为量化存活心肌的指标。筛选 4 8例初次急性心肌梗死患者 ,心肌梗死后 (2 0± 12 )天成功的接受梗死相关血管的介入治疗术 ,术前 1～ 3天接受静息超声心动图和小剂量多巴酚丁胺负荷超声心动图检查 ,术后 (5 4± 1 6 )个月复查静息超声心动图。依小剂量多巴酚丁胺超声心动图负荷试验检测出的梗死相关的异常室壁节段中存活心肌的节段数 ,将 4 8例患者分为 :Ⅰ组 ,大量存活心肌 (存活心肌节段≥ 6段 ) 11例 ,Ⅱ组 ,少量存活心肌 (2段≤存活心肌节段≤ 5段 ) 2 9例 ,Ⅲ组 ,无存活心肌 (存活心肌节段 <2段 ) 8例。分别测定术前和术后静息状态下的左室舒张末容积、左室收缩末容积、左室射血分数和左室室壁节段运动积分指数。结果 重建血管术后 (5 4± 1 6 )个月随访发现梗死相关动脉血管重建后 ,梗死相关血管的异常室壁运动有不同程度的改善 ,Ⅰ组的左室收缩末容量由 (6 3± 8)ml降至 (4 7± 10 )ml(P <0 0 1) ;室壁运动积分指数由 1 4± 0 2降至 1 1± 0 1(P <0 0 1) ,左室射血分数由 (4 6± 9) %增至 (5 7± 10 ) % (P<0 0 1)。Ⅱ组的左室收缩末容量

Objective To evaluate the effects of myocardial viability of dysfunctional myocardium on l eft ventricular remolding and global function after successful revascularization in patients with acute myocardial infarction(AMI). Methods Interventional revascularization was done successfully for 48 patients with fi rst AMI 20±12 days after onset. 1 to 3 days before operation, echocardiography and low-dose dobutamine stress echocardiography were performed for all the pat ients and the same follow-up examination was carried out 5.4±1.6 months afte r operation. The segments of viable myocardium and the wall motion score index were assessed according to 16 segments scored way on left ventricular wall recom mended by American Society of Echocardiography. Based on the numbers of segmen ts of viable myocardium, 48 patients were divided into 3 groups: groupⅠ(11 case s), with more than 6 segments of viable myocardium; groupⅡ(29 cases) with 2 to 5 segments of viable myocardium; and group Ⅲ (8 cases) with less than 2 segmen ts of viable myocardium. At the same time, the left ventricular end-diastolic v olume (LV-EDV), the left ventricular end-systolic volume (LV-SDV), the ejecti on fraction (EF) and the wall motion score index were measured on echoca rdiography at 20±12 days and 5.4±1.6 months after AMI. Resu lts Follow up at 5.4±1.6 months after successful revascularization showed that there was a recovery of left ventricular volume and function. In gr oupⅠ, the LV-ESV decreased from 63 ml to 47 ml(P<0.01);the left ventri cular wall motion score index decreased from 1.4 to 1.1(P<0.01); and th e LV-EF increased from 46% to 57 %_(P<0.01). In groupⅡ, the LV-ESV decreased from 72 ml to 64 ml (P<0.01);the left ventricular wall motion score index decreased from 1.6 to 1.4(P<0.01); and the LV-EF increased from 45% to 51 %_(P<0.05). In group Ⅲ, no obvious changes occurred except that the LV-EDV increased from 145 ml to167 ml(P<0.05). C onclusion Functional recovery of viable myocardium after AMI is importa nt in the maintenance of the left ventricular modality and function. The number of viable myocardium segments assessed by low-dose dobutamine stress echocardio graphy can be used as the parameter in quantifying viable myocardium and in pred icting the ventricular remodeling and ventricular function after revascularizati on.