Myocardial bridges and their relationship to the anterior interventricular branch of the left coronary artery.
OBJECTIVE
To analyze the relationship between myocardial bridges and the anterior interventricular branch (anterior descending) of the left coronary artery.


METHODS
The study was carried out with postmortem material, and methods of dissection and observation were used. We assessed the perimeter of the anterior interventricular branch of the left coronary artery using a pachymeter, calculated its proximal and distal diameters in relation to the myocardial bridge, and also its diameter under the myocardial bridge in 30 hearts. We also observed the position of the myocardial bridge in relation to the origin of the anterior interventricular branch.


RESULTS
The diameters of the anterior interventricular branch were as follows: the mean proximal diameter was 2.76+/-0.76 mm; the mean diameter under the myocardial bridge was 2.08+/-0.54 mm; and the mean distal diameter was 1.98+/-0.59 mm. In 33.33% (10/30) of the cases, the diameter of the anterior interventricular branch under the myocardial bridge was lower than the diameter of the anterior interventricular branch distal to the myocardial bridge. In 3.33% (1/30) of the cases, an atherosclerotic plaque was found in the segment under the myocardial bridge. The myocardial bridge was located in the middle third of the anterior interventricular branch in 86.66% (26/30) of the cases.


CONCLUSIONS
Myocardial bridges are more frequently found in the middle third of the anterior interventricular branch of the left coronary artery. The diameter of the anterior interventricular branch of the left coronary artery under the myocardial bridge may be smaller than after the bridge. Myocardial bridges may not provide protection against the formation of atherosclerotic plaque inside the anterior interventricular branch of the left coronary artery.
Lima
Vanildo Júnior de Melo
VJ
Centro de Ciências Biológicas, UFPE, Recife, PE. vjr@npd.ufpe.br
Cavalcanti
Jennecy Sales
JS
Tashiro
Tetsuo
T
D000328:Adult; D003331:Coronary Vessels / Q000033:anatomy & histology*; D005260:Female; D006321:Heart / Q000033:anatomy & histology*; D006352:Heart Ventricles / Q000033:anatomy & histology; D006801:Humans; D008297:Male; D009206:Myocardium