心肌灌注显像对症状性冠状动脉心肌桥患者的临床应用价值

目的 探讨心肌灌注显像对症状性冠状动脉(以下简称冠脉)心肌桥患者的临床应用价值.方法 回顾性分析19例因胸痛、胸闷等症状行冠脉造影排除阻塞性冠脉狭窄,诊断为心肌桥并接受运动-静息99Tcm-甲氧基异丁基异腈(MIBI)心肌灌注显像的患者资料,分析心肌灌注显像结果,并与运动心电图、冠脉造影结果比较.应用Stata 7.0软件,对符合正态分布的计量资料行t检验比较,用χ2检验分析组间频数差别.结果 19例症状性心肌桥患者冠脉造影示收缩期冠脉狭窄程度为(65.4±22.1)%,18例为左前降支肌桥、1例为左前降支合并左回旋支肌桥.运动-静息心肌灌注显像示心肌缺血10例、正常9例,其中心肌缺血位于前壁和(或)心尖部8例、下壁1例、后侧壁和后间壁1例;心肌灌注显像诊断心肌缺血的阳性率为52.6%(10/19),明显高于运动心电图的21.1%(4/19)=4.07,P<0.05.19例心肌桥患者按Nobel分级法,Ⅰ级狭窄5例、Ⅲ级狭窄6例、Ⅲ级狭窄8例;Ⅰ级狭窄患者中1例心肌灌注显像心肌缺血阳性,Ⅱ级狭窄患者中2例阳性,Ⅲ级狭窄患者中7例阳性.心肌桥患者心肌灌注显像心肌缺血组收缩期冠脉狭窄明显高于心肌灌注显像正常组(78.0±4.7)%与(52.8±6.7)%,t=3.06,P<0.01],2组肌桥长度差异无统计学意义(15.1±2.1)mm与(11.8±1.0)mm,t=1.43,P>0.05].结论 运动-静息心肌灌注显像能有效评价症状性心肌桥患者所致心肌缺血,明确心肌桥与临床症状的关系及其临床意义.

The clinical application value of myocardial perfusion imaging in evaluating coronary artery myocardial bridge patients with symptoms

Objective Myocardial bridge is a common inborn coronary artery anomaly, myocardial bridge may be associated with myocardial ischemia. Only a few patients with coronary artery myocardial bridge were evaluated with nuclear medicine techniques. The aim of this study was to investigate the role of nuclear cardiology with myocardial perfusion technique in symptomatic myocardial bridge patients. Methods Nineteen myocardial bridge patients with the symptoms of chest pain and chest distress were analyzed retro-spectively. 99Tcm-methoxyisobutylisonitrile (MIBI) myocardial perfusion images (both exercise and rest)were performed in all. Imaging results were compared with the results of movement electrocardiogram (ECG) and coronary arteriography. The t test orx χ2 test was used to statistically analyze the data with Stata 7.0 software. Results Of the 19 patients, 18 patients had myocardial bridge locating at the left anterior descending artery, 1 patient at the left anterior descending and left circumflex artery, the mean angiographic systolic occlusion within the myocardial bridge was (65.4±22.1) %. Of these 19 patients, Exercise-rest 99Tcm-MIBI myocardial perfusion imaging defined positive myocardial ischemia in 10 and negative in 9 pa-tients. Of the 10 patients with 99Tcm-MIBI myocardial perfusion imaging defined myocardial ischcmia, 8 had reversible radioactive defect of partial anterior wall and(or) apex, 1 had reversible defect of post lateral wall and post septal wall, and 1 had reversible defect of inferior wall. The positive predictive value of myocardial perfusion imaging was 52.6% (10/19), which was higher than movement ECG 21.1% (4/19), χ2=4.07, P<0.05]. Of the 19 cases, according to the Nobel grading, 5 cases with grade Ⅰ stenosis, one was 99Tcm-MIBI myocardial perfusion imaging defined myocardial iscbemia. Six cases with Grade Ⅱ stenosis, two were 99Tcm-MIBI myocardial perfusion imaging defined myocardial ischemia. Eight cases with Grade Ⅲ ste-nosis, seven were 99Tcm-MIBI myocardial perfusion imaging defined myocardial ischemia. The mean anglo-graphic systolic occlusion within the myocardial bridge was significantly higher in patients with myocardial ischemia on myocardial perfusion imaging than in those with normal myocardial perfusion imaging (78.0±4.7)% vs (52.8±6.7)%, t=3.06, P<0.01] the lengths of myocardial bridges had no difference in patients with myocardial ischemia compared with those with normal myocardial perfusion imaging (15.1±2.1) mm vs (11.8±1.0) mm, t=1.43, P>0.05]. Conclusion 99Tcm-MIBI myocardial perfusion im-aging had higher detection rate of myocardial bridging than movement ECG in symptomatic patients.