The hyaluronic acid in intramyocardial sliding

Abstract

Introduction and objectivesThe sliding between internal and external segments of the myocardium assumes opposite directions in their movements, during the systolic and suction phases of the heart, generating friction. Our objective was to considerer the possibility of the existence of a lubricant that prevents friction wear in myocardial torsion and detorsion movements. MethodsTwenty-four hearts were used: (a) Fifteen two-year-old bovine hearts weighing 800–1000g. (b) 9 human hearts (two 16- and 23-week gestation embryos, one from a 10-year-old child weighing 250g and 6 from adults, with an average weight of 300g). In the hearts 5 transverse, 2cm thick sections were made from base to apex to analyze the hyaluronic acid. All samples were subjected to histochemical analysis with Alcian blue staining, a reliable marker to identify the presence of hyaluronic acid, as an antifriction mechanism and even to provide a semi-quantitative assessment. ResultsIn all the hearts analyzed, hyaluronic acid was found in the cleavage planes between the myocardial bundles. Histological and histochemical studies of the myocardium and its ducts (Thebesian and Langer) have shown that hyaluronic acid could be considered the antifriction effect, which flows throughout the myocardial thickness. ConclusionsThis process involves opposite directions of the muscle segments and of these against the septal area. Sliding between these segments assumes opposite courses during the phases of the cardiac cycle (systole and suction) generating friction. In order to carry out this work, there is an antifriction lubricating mechanism represented by the venous Thebesian and Langer ducts together with the presence of hyaluronic acid. It is understandable that the fascicles of the myocardium, one on top on the other but in discordant directions, implies that the friction between them without a lubricating mechanism would be a decrease in the capacity of movement due to friction.