Coronary arteries; myocardial bridges; Morphometry; Human anatomy.

The cardiovascular system is one of the noble systems of the human body. As a key part of its functioning, we have the heart working as a contractile pump to circulate blood throughout the body. To irrigate and nourish this organ, on its surface we find the coronary arteries (CA). However, in some cases, anatomical variations are identified in these vessels called myocardial bridges (MP). This occurs when myocardial fibers overlap these vessels, tunneling them. In most cases, this condition is asymptomatic and has a good prognosis, but it can also be associated with various pathological clinical scenarios and even sudden death. In this sense, morphometric studies that metrically characterize these variations and these vessels as a whole are of immense clinical and surgical relevance to support professional care practices. Thus, this research aims to perform the morphometry of the coronaries and PM of human hearts at the Anatomy Laboratory of the Federal University of Rio Grande do Norte. This is a cross-sectional descriptive quantitative study, in which 216 human hearts fixed in 10% formaldehyde were dissected and analyzed. 92 MB were found in 86 hearts, of which 82 were in the anterior interventricular artery (89.13%). Along with studying the incidence and morphometry of the PM, we also took measurements of the AC and interventricular arteries (IA). The right AC measured an average of 123.59 mm; the left AC measured an average of 12.11 mm; The anterior AI measured an average of 107.07 mm; and the posterior AI measured an average of 55.26 mm.