title: Association of variance in anatomical elements of myocardial bridge with coronary atherosclerosis.
abstract: OBJECTIVE
  The myocardial bridge (MB) is an anatomical structure consisting of myocardium covering a part of the left anterior descending coronary artery (LAD). The extent and spatial distribution of atherosclerosis in the LAD with an MB is influenced by the anatomical properties of the MB. In this study, the relationship between the overall anatomical framework of the MB including the periarterial adipose tissue as well as fibrosis of the MB itself and coronary atherosclerosis was histomorphometrically examined.
  
  
  METHODS
  Full-length LADs with an MB from 180 autopsied hearts were cross-sectioned at 5-mm intervals. Together with measurements of MB - length, thickness, and location, proportional decrease of the atherosclerosis ratio of LAD segments beneath MB for that of LAD segments proximal to MB was defined as the atherosclerosis suppression ratio. The area ratio of adipose tissue in the periarterial area beneath MB and area ratio of fibrosis in the MB muscle were also measured.
  
  
  RESULTS
  The atherosclerosis suppression ratio was significantly proportional to MB length and thickness. Periarterial adipose tissue beneath MB was detected in all cases (100%), and fibrosis within MB muscle for 136 cases (75.6%). The amount of adipose tissue beneath MB and MB fibrosis did not statistically affect the atherosclerosis suppression ratio. Multivariate analysis revealed MB length and thickness were the independent factors affecting the atherosclerosis suppression ratio.
  
  
  CONCLUSIONS
  The anatomical properties of an MB, especially of its length and thickness, play decisive roles as regulators of atherosclerosis in the LAD regardless of the amount of adipose tissue around LAD and MB fibrosis.
authors: Department of Pathology, Toho University School of Medicine, 5-21-16 Omori-Nishi, Ota-ku, Tokyo 143-8540, Japan. ami.iuchi@med.toho-u.ac.jp
authors: Ami
authors: A
authors: Iuchi
authors: Yukio
authors: Y
authors: Ishikawa
authors: Yuri
authors: Y
authors: Akishima-Fukasawa
authors: Ryuji
authors: R
authors: Fukuzawa
authors: Yoshikiyo
authors: Y
authors: Akasaka
authors: Toshiharu
authors: T
authors: Ishii
mesh_terms: D000273:Adipose Tissue / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001344:Autopsy; D003324:Coronary Artery Disease / Q000473:pathology*; D003330:Coronary Vessel Anomalies / Q000150:complications / Q000473:pathology*; D003331:Coronary Vessels / Q000473:pathology*; D005260:Female; D005355:Fibrosis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology