Zoghi Mehdi, Duygu Hamza, Nalbantgil Sanem, Kirilmaz Bahadir, Turk Ugur, Ozerkan Filiz, Akilli Azem, Akin Mustafa, Turkoglu Cuneyt
Department of Cardiology, Ege University Medical Faculty, Izmir, Turkey.
Echocardiography. 2006 Aug;23(7):577-81. doi: 10.1111/j.1540-8175.2006.00279.x.
The relationship between myocardial bridging (MB) and ischemic heart disease is still controversial. In this study, we aimed to evaluate the existing atherosclerosis and noninvasive endothelial function of brachial artery in patients with MB.
The present study included 50 patients (group I) who had MB in left anterior descending (LAD) on coronary angiography. All of the coronary artery segments were evaluated by intravascular ultrasound (IVUS). Endothelial function was assessed with measurement of flow-mediated dilatation (FMD) and nitrate-dependent dilatation in the brachial artery. The study also included 30 healthy control subjects (group II). Patients in the group I were further subdivided into two subgroups based on the findings on IVUS: group IA included 20 patients without atherosclerotic lesions and group IB included 30 patients with atherosclerotic coronary artery disease in addition to MB.
FMD values were found to be significantly lower in the patients with MB (group I) than in the control (6.4 +/- 3% vs 11 +/- 4%, P <0.001). In regard to FMD values in subgroups, FMD was 7 +/- 2% in the group IA and 5.8 +/- 1% in the group IB (P = 0.023). On IVUS, atherosclerotic plaque was found proximal to the bridge in the same coronary artery segment in addition to MB in 75% of the patients in group I (group IB). No atherosclerotic plaque was found in within or distal segments of MB.
Endothelial function is impaired in patients with MB and there is an increased tendency for atherosclerosis proximal to the bridge in the patients with MB. Endothelial dysfunction is more severe in the patients with atherosclerosis proximal to the bridge.
心肌桥（MB）与缺血性心脏病之间的关系仍存在争议。在本研究中，我们旨在评估MB患者肱动脉的现有动脉粥样硬化情况及无创内皮功能。
本研究纳入50例经冠状动脉造影显示左前降支（LAD）存在MB的患者（I组）。所有冠状动脉节段均通过血管内超声（IVUS）进行评估。通过测量肱动脉的血流介导的血管舒张（FMD）和硝酸酯依赖性血管舒张来评估内皮功能。该研究还纳入了30名健康对照者（II组）。I组患者根据IVUS检查结果进一步分为两个亚组：IA组包括20例无动脉粥样硬化病变的患者，IB组包括30例除MB外还患有动脉粥样硬化性冠状动脉疾病的患者。
发现MB患者（I组）的FMD值显著低于对照组（6.4±3%对11±4%，P<0.001）。关于亚组的FMD值，IA组为7±2%，IB组为5.8±1%（P = 0.023）。在IVUS检查中，I组（IB组）75%的患者除MB外，在同一冠状动脉节段桥近端发现动脉粥样硬化斑块。在MB内或远端节段未发现动脉粥样硬化斑块。
MB患者存在内皮功能受损，且MB患者桥近端动脉粥样硬化倾向增加。桥近端有动脉粥样硬化的患者内皮功能障碍更严重。
