左前降支心肌桥对冠状动脉硬化斑块分布的影响

Effects of Left Anterior Descending Myocardial Bridges on the Atherosclerotic Plaques of Coronary Artery

目的探讨左前降支心肌桥(LAD-MB)与冠状动脉粥样硬化的关系。方法回顾性分析本院2013年5月至2014年5月冠状动脉CTA资料823例,其中LAD-MB完全包绕型199例(A组)、不全包绕型55例(B组),无MB者569例(C组)。利用容积再现(VR)、曲面重组(CPR)、多平面重组(MPR)等三维技术显示LAD-MB,统计冠状动脉硬化斑块发生率,观察LAD斑块特点,相关数据进行统计学χ2检验。结果 LAD-MB 254例,发现MB 269处,近、中、远段分别为3(1.1%)、246(91.5%)、20(7.4%)处。A、B、C组中LAD、PDA、LCX粥样硬化发生率分别为51.8%、47.3%、47.5%;32.2%、25.5%、28.1%;29.6%、20%、20.9%;A组、B组在LAD-MB近侧段、MB段、MB远侧段的硬化发生率分别为51.8%、0.5%、4.5%;47.3%、0%、1.8%;组内比较有显著性差异(P<0.05),组间无差异(P>0.05)。A、B、C组LAD近段、中段、远段硬化发生率分别为44.7%、19.1%、2.5%;36.4%、20%、1.8%;40.2%、26.7%、0.5%;A+B组与C组比较,近段发生率无统计学差异,中段、远段发生率有统计学差异(P<0.05)。结论 LAD-MB的存在不影响冠状动脉各支粥样硬化的发生率,其LAD斑块分布MB近侧段多于MB段及MB远侧段。与对照组比较,斑块发生率LAD中段低、而远段高,后者可能导致左心室心尖及下壁的缺血。

Objective To discuss the correlation between the left anterior descending coronary artery myocardial bridges （LAD-MB） and coronary atherosclerosis. Methods CTA data of 823 cases, of which 199 cases with the complete LAD- MB in group A, 55 with the incomplete in B and 569 with no MB in C from May 2013 to May 2014 in our hospital, were analyzed retrospectively. LAD-MB was shown with the techniques of three-dimensional volume rendering （ VR）, curved plane reformation （Curved） and multi-planar reformation （MPR）. The incidence of coronary atherosclerotic plaques was calculated and characteristics of plaques on LAD were observed. 569 cases without MB were regarded as control group C. The chi-square test was used. Results 269 sites of LAD-MB were detected in 254 cases, of which 85.9% were located at the mid LAD. Atherosclerosis incidence of LAD, PDA, LCX in the A, B, C group was 51.8%, 47.3%, 47.5% ; 32.2% , 25.5% , 28.1% ; 29.6% , 20% , 20.9% , respectively. The atherosclerosis incidence of LAD proximal-MB, MB, distal-MB in A and B groups was 51.8% , 0.5% , 4.5% and 47.3% ,0% ,1.8%. There were significant differences in the proximal-MB, MB, distal-MB of LAD, but no difference between group A and B. Atherosclerosis incidence of proxi- mal, middle, distal segment of LAD in group A, B, C were 44.7%, 19. 1% ,2.5% ; 36.4% ,20% , 1.8% ; 40.2% , 26.7% ,0.5% , respectively. There was no significant difference in the proximal segment between group A ＋ B and C, but there was statistical difference in the middle and distal （P 〈 0.05）. Conclusion LAD-MB would not influence the ather- osclerosis incidence of coronary artery. Atherosclerosis incidence of MB group is more on the proximal segment of LAD than on the MB or distal segment. Compared with control group, the atherosclerosis incidence is lower on mid-segment and high- er on distal, which would cause left ventricular apex and inferior wall ischemia.