64层螺旋CT冠状动脉血管成像评估心肌桥

目的运用64层螺旋CT冠状动脉成像描述壁冠状动脉在舒张期受压情况，探讨心肌桥与冠状动脉粥样硬化形成关系。方法分析611例行冠状动脉CTA扫描病人，对心肌桥长度、厚度，壁冠状动脉在舒张期受压及其伴随的动脉粥样硬化情况进行评估。分析壁冠状动脉舒张期受压与动脉粥样硬化形成的相关性。并按心肌桥存在与否进行分组配对，比较有心肌桥组动脉粥样硬化发生率与无心肌桥组动脉粥样硬化发生率。结果611例病人中173例发现心肌桥（28．3％）。左前降发生率最高（122／173）。舒张中期壁冠状动脉重度受压者心肌桥厚度与无或轻度受压心肌桥厚度存在显著差异性（P=0．016）。壁冠状动脉受压情况与动脉粥样硬化斑块所致狭窄程度存在正相关关系（r=0．842，P=0．002）。邻近心肌桥段冠状动脉粥样硬化发生率与单纯冠状动脉粥样硬化发生率存在显著性差异（P=0．017）。结论心肌桥厚度与壁冠状动脉舒张期受压程度及邻近冠状动脉斑块形成相关；心肌桥可能是评估冠心病的危险因素之一。

Evaluation of myocardial bridge on 64-slice CT coronary angiography

Objective To discribe the change of tunnelled artery at diastolic stage by CT coronary angiography and to evaluate the relationship between myocardial bridge and the formation of coronary atherosclerotic plaque. Methods Six hundred and eleven patients were involved in this study. The length,thickness, precise location, compression of myocardial bridge, and concomitant atheromatous changes were evaluated. A correlation between diastolic narrowing of tunnelled artery and formation of coronary atherosclerotic plaque were analyzed.The group in which patients had myocardial bridge were compared with another group did not have myocardial bridge. The probability of atherosclerotic plaque between patients in two groups was compared. Results One hundred and seventy three paients (28.3%) were found to have myocardial bridge among 611 subjects.Most of them located in left anterior descending artery (122/173). The thickness of myocardial bridge in patients with moderate or severe stenosis was significant higher than that in patients with normal or mild stenosis (P=0.016). There was positive correlation between diastolic narrowing of tunnelled artery and percentage of its atherosclerotic stenosis (r=0.842, P=0.002). A significant difference was found between the LAD myocardial bridge group and control group regarding presence of atheromatous changes (P=0.017). Conclusion The thickness of myocardial bridge correlates with stenostic narrowing of tunnelled artery and the possibility of coronary atherosclerotic plaque formation. Myocardial bridge predisposes to the development of atherosclerosis in the coronary artery segment proximal to the bridge. Myocardial bridge may be considered a risk factor in the evaluation of coronary artery disease.