New aspects concerning the morphology and significance of coronary muscle bridges.

Intramural courses of the coronary arteries in the sense of coronary muscle bridges are frequent autopsy findings, whereas only the more pronounced forms are accessible to clinicoangiographic detection. Functional significance is attributable to morphologic forms that show a pronounced intramural course and to those exhibiting quantitative cross-sectional changes. In addition to the known morphometric findings in the case of coronary muscle bridges, we found a stenosis-like narrowing of intramurally coursing arteries without alterations of the intima. We observed such quantitative coronary artery findings in four cases with different causes of death, and in this paper we discuss the possible functional significance of this special type of coronary muscle bridge.