Incidence and clinical significance of bridges of myocardium over the coronary arteries and their branches

Abstract

The incidence of bridges of myocardium seen on the external surface of the heart, through the epicardium, over portions of coronary arteries and their branches, was studied in 50 cadavers and found to be 78%. The bridges of the myocardium varied in size and in number (from one to six). Their location was predominantly found at the level of the anterior ventricular branch of the left coronary artery also called left anterior descending artery (52%), whereas in the territory of the right coronary artery the highest percentage was at the level of the anterior ventricular branch (12%). This myocardio-arterial relationship might be responsible for periodic or permanent reduction of the lumen, partial or total arterial obliteration, ischemia, atherosclerosis, angina, and sudden death.

Characterisation of myocardial bridges in pigs: a comparative anatomical analysis with the human heart

“…The findings of MB in the present study (42.4%) are located in the middle of the 24-86% range reported in prior studies for this morphologic expression [1,5,21]. The frequency of MB in humans, as with pigs, has been reported along a wide range of 23-88% [2,7,8,12,24,27,28,31,33].…”

“…The organs were subjected to an exsanguination process in a water source for 6 h. Upon repair with silk at their origin, the CA of the hearts studied were channelled through their ostium and perfused with polyester resin (palatal GP41L 80% and styrene 20%) course of the coronary arteries (CA) and their branches [7,21,22,32]. MB can induce ischaemia in the areas localised distally to them, due to compression impregnated with mineral red.…”

“…The presence of 2 MB in the same vessel is a rare occurrence [21]. The frequency of these muscle bands in pigs is 24-86% [1,5,21], whereas in humans they have been reported with a frequency of 23-88%, a variability that could be attributed to the diverse techniques utilized for their evaluation or to an ethnic feature of the population groups studied [2,7,8,12,24,27,28,31,33].…”

Coronary artery distribution in Macaca fascicularis (Cynomolgus)

“…Mills 1978, Lambie 1980, Hadziselimovie 1981, DiDio &. Rodrigues 1983, Ishii et al 1986, Bezerra et al 1987, Baptista et al 1989). …”

Chronic Degenerative Changes in the Myocardium Supplied by Bridged Coronary Arteries in Eight Postmortem Samples

“…There are reports of a wider range of clinical manifestations, ranging from no symptoms to sudden death. [5][6][7] Some researchers claim that the blood supply to myocardium occurs mainly on diastole, so the myocardial bridge will not cause any symptoms 5,8 whereas others accept the diastolic blood supply phenomenon but believe that myocardial ischemia may occur due to systolic narrowing greater than 75% and heart rates over 150 beats/min. 9 The term ischemia, used in studies on myocardial bridges, defines acute ischemic diseases of the heart (angina pectoris, myocardial infarction and sudden cardiac death).…”