Myocardial bridges: a prospective forensic autopsy study.

Introduction: When the coronary artery, located subepicardially, submerges into the myocardium and appears again subepicardially after a short intramural course, it represents an embedded coronary artery, while the part of the myocardium above is a myocardial bridge.

Objective: We investigated the frequency of the embedded left coronary artery (LAD) in the autopsy material considering the descending branch of the LAD to be the most important one in the nourishment of the myocardium and myocardial bridges to be the most frequent in its area, as well as clinically important.

Methods: A prospective autopsy study of 975 cases was performed, including both, natural (21.33%) and violent (78.67%) deaths. The sample consisted of 74.56% males and 25.44%females. In order to discover myocardyal bridges and their characteristics, the hearts were examined by both transverse cuts and longitudinal openings of the LAD.

Results: Myocardial bridge was found in 78 cases (8.00%), more commonly in males (9.35%) than females (4.03%).The average length of the myocardial bridge was 21.85±16.10mm and thickness 3.744±1.48 mm. The common localization of the myocardial bridge was the proximal half of the LAD (89.74%).The upper part of the artery, proximal to the bridge, was a common site of atherosclerotic changes. Myocardial bridge was found in 12.50% of natural deaths, but in 13.38% out of all cases of sudden cardiac deaths.

Conclusion: Therefore, the presence of the myocardial bridge by itself is not predominant, but it is certainly a contributing factor to a sudden cardiac death.