[Macro- and microscopic characteristics of the intramyocardial course of the coronary arterie]

To establish patterns of macro- and microscopic anatomy and topography of myocardial bridges over the coronary arteries and their branches according to coronary angiography data and on preparations of hearts of adults of both sexes.

An observational, retrospective, non-randomized study was conducted. The frequency of myocardial bridges over the coronary arteries and their branches was studied according to the data of retrospective analysis of the results of coronary angiography (1986 protocols), morphological study was performed on 30 isolated preparations of the hearts of adults of both sexes (18 women and 12 men) aged from 31 to 99 years (median 70). The trunks of the right and left coronary arteries and their branches were isolated by the method of dissection. The presence of myocardial bridges over the branches of the coronary arteries was detected, their length and the thickness of the myocardium over the branches of the arteries were recorded. A histological examination of the heart areas with detected myocardial bridges was performed. It was found that the frequency of detection of myocardial bridges during coronary angiography is significantly lower than their occurrence during autopsy.

The presence of myocardial bridges in the right coronary artery system may correlate with its presence in the left coronary artery system and other abnormalities in heart development. Myocardial bridges are more common in men and are mainly localized in the middle third of the anterior interventricular branch of the left coronary artery. Isolated myocardial bridges are more common. The length of myocardial bridges on average ranges from 9.2 to 22.3 mm, the thickness - from 0.2 to 3 mm. A relationship has been found between the length of the bridges and the dimensions of the ventricular complex of the heart. The intramural segment of the coronary artery is usually completely immersed in the myocardium, but sometimes a semi-tunnel passage occurs, in which the coronary artery is covered by myocardium by 2/3 or 3/4 of the circumference of its cross-section. In all sections of the coronary arteries of the heart, regardless of their location in relation to the myocardial bridge, there was atherosclerotic lesion of the coronary artery of varying degrees of severity.