Anatomic Properties of Myocardial Bridge Predisposing to Myocardial Infarction

• DOI: 10.1161/circulationaha.108.820720
• Publication Date: 2009-07-21T01:10:56Z
• Authors: Yukio Ishikawa; Yoshikiyo Akasaka; Koyu Suzuki; Mieko Fujiwara; Takafumi Ogawa; Kazuto Yamazaki; Hitoshi Niino; Michio Tanaka; Kentaro Ogata; Shojiroh Morinaga; Yoshiro Ebihara; Yutaka Kawahara; Hitoshi Sugiura; Toshiro Takimoto; Akio Komatsu; Toshihito Shinagawa; Kazuhiro Taki; Hideaki Satoh; Kazuaki Yamada; Maki Yanagida-Iida; Reiko Shimokawa; Kazuyuki Shimada; Chiaki Nishimura; Kinji Ito; Toshiharu Ishii
• Keywords: Ostium; Myocardial bridge; Coronary atherosclerosis

A myocardial bridge (MB) that partially covers the course of left anterior descending coronary artery (LAD) sometimes causes ischemia, primarily because hemodynamic deterioration, but without atherosclerosis. However, mechanism occurrence infarction (MI) as a result an MB in patients with spontaneously developing atherosclerosis is unclear.One hundred consecutive autopsied MI hearts either MBs [MI(+)MB(+) group; n=46] or (n=54) were obtained, 200 normal hearts, 100 [MI(-)MB(+) group] and MBs. By microscopy on LADs consecutively cross-sectioned at 5-mm intervals, extent distribution LAD investigated histomorphometrically conjunction anatomic properties MB, such its thickness, length, location muscle index (MB thickness multiplied by length), according to status. In MI(+)MB(+) group, showed significantly greater (P<0.05) than MI(-)MB(+) group. The intima-media ratio (intimal area/medial area) within 1.0 cm ostium was also group other groups. addition, segment exhibited greatest proximal correlated (P<0.001) entrance, furthermore, progression largest 2.0 from entrance.In associated shift disease more proximally, effect may increase risk MI.