Myocardial bridging (milking effect) in left anterior descending coronary artery causing acute coronary syndrome

Abstract

Coronary arteries generally have an epicardial pathway. When they go deep into the thickness of heart muscles they form the so-called muscular bridges or intramyocardial courses. During systole, these bridges significantly reduce the vessel light and produce a dynamic extrinsic compression, known as milking phenomenon; which appears more frequently in the left anterior descending artery, especially in its mid and distal segments. Although milking may be a rare phenomenon the incidence of intramyocardial course in necropsy samples ranges from 34-52%. Its evolution is quite favorable although, in some patients, its presentation may range from precordial pain to sudden death. Until now, the use of beta-blockers seems to be the most viable therapeutic alternative. The case of a patient with this condition is presented in this article.