Harikrishnan S, Sunder K R, Tharakan J, Titus T, Bhat A, Sivasankaran S, Bimal F
Department of Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram.
Indian Heart J. 1999 Sep-Oct;51(5):503-7.
Myocardial bridging describes an angiographic entity, which is any degree of systolic narrowing of a coronary artery observed in at least one angiographic projection. Among the cineangiograms of 3200 patients reviewed, there were 21 cases (19 males) of myocardial bridges--incidence of 0.6 percent. Of these, seven had hypertrophic cardiomyopathy, six had atherosclerotic coronary artery disease and remaining eight had no evidence of either. All 21 patients had myocardial bridges in proximal or mid left anterior descending coronary artery. In addition, one case of hypertrophic cardiomyopathy had whole posterior descending coronary artery under a myocardial bridge. Another case of hypertrophic cardiomyopathy had a short normal segment of 5 mm inside a long myocardial bridge of 35 mm (tandem myocardial bridges). The length of the bridges varied from 10 to 35 mm (mean 24.5 +/- 4.5 mm) and diameter stenosis during systole varied from 40-90 percent (mean 70 +/- 8%). Two patients had large saccular coronary aneurysms proximal to the muscle bridge. Four of the eight patients who had neither hypertrophic cardiomyopathy nor coronary artery disease presented with acute anterior wall myocardial infarction and three of them had regional wall motion abnormality of left descending territory. Of the six patients who had coronary artery disease, one had 60 percent left descending artery lesion and two had recanalized segments proximal to the bridge. Five of the above six patients had significant stenosis of other coronary vessels. Four patients were lost to follow-up (mean period 3.4 +/- 2 years). In the coronary artery disease group, one patient underwent coronary artery bypass graft surgery for 3-vessel disease including graft to left descending artery and one developed inferior wall myocardial infarction. The patients in the hypertrophic cardiomyopathy group and "no hypertrophic cardiomyopathy-no coronary artery disease" group were free of events at last follow-up. Long-term prognosis of isolated myocardial bridges appears to be excellent. Degree of systolic narrowing or length of myocardial bridge does not correlate with event rates on follow-up.
心肌桥描述的是一种血管造影表现，即在至少一个血管造影投照位上观察到冠状动脉出现任何程度的收缩期狭窄。在回顾的3200例患者的电影血管造影片中，有21例（19例男性）心肌桥，发生率为0.6%。其中，7例患有肥厚型心肌病，6例患有动脉粥样硬化性冠状动脉疾病，其余8例无上述两种疾病的证据。所有21例患者的心肌桥均位于左前降支冠状动脉近端或中段。此外，1例肥厚型心肌病患者的整个后降支冠状动脉位于心肌桥下。另1例肥厚型心肌病患者在35毫米长的心肌桥内有一段5毫米长的正常节段（串联心肌桥）。心肌桥长度为10至35毫米（平均24.5±4.5毫米），收缩期直径狭窄率为40%至90%（平均70±8%）。2例患者在肌桥近端有巨大囊状冠状动脉瘤。8例既无肥厚型心肌病也无冠状动脉疾病的患者中有4例发生急性前壁心肌梗死，其中3例有左降支区域室壁运动异常。6例患有冠状动脉疾病的患者中，1例左降支动脉病变达60%，2例在肌桥近端有再通节段。上述6例患者中有5例其他冠状动脉有明显狭窄。4例患者失访（平均随访期3.4±2年）。在冠状动脉疾病组中，1例因三支血管病变接受冠状动脉搭桥手术，包括搭桥至左降支动脉，1例发生下壁心肌梗死。肥厚型心肌病组和“无肥厚型心肌病-无冠状动脉疾病”组的患者在最后一次随访时均无事件发生。孤立性心肌桥的长期预后似乎良好。收缩期狭窄程度或心肌桥长度与随访事件发生率无关。
