Congenital morphological patterns of myocardial bridges

Abstract

Myocardial bridging (MB) is a coronary anomaly in which a segment of the coronary artery is overlapped by a layer of myocardial tissue. Nowadays, there is no scientific agreement on if the MB are congenital or acquired or on the factors that determine their presence and/or absence. This study is performed to analyze the anatomical characteristics of adult and children's hearts regarding the shape of the left coronary artery branching, presence of pre-bridge arterial branch, coronary dominance and its correlations to MB formation. We analyzed 240adults heart specimens and 63children's specimens. The frequency of the myocardial bridges (MB) occurrence was performed through observational study of the anatomical specimens. The shape of the left coronary artery (LCA) branching, presence of pre-bridge arterial branch (PBB) and coronary dominance was determined superficial dissection of the epicardial adipose tissue and careful evaluation of the hearts. A relation between the trifurcated pattern of the LCA and the presence of MB (P<0.0001, odds ratio=3.74) was found in adults heart and in children's hearts (P=0.003, odds ratio=16.0), as well as a relation between the presence of PBB and the presence of MB in adult hearts (P<0.0001) and children's hearts (P<0.0001). Our findings suggest for the first time that the myocardial bridges are related to the presence of trifurcation of the left coronary artery and the pre-bridge arterial branch in adult and children's hearts.