What is the in vivo axial strain of a porcine coronary artery?

Knowledge of mechanical properties of livingarteries is important to understand vascular functionduring health and disease. An effective way tostudy the behavior of living tissue is organ culture.In arterial culture the artery should be loaded at invivo levels to maintain the arterys viability. The invivo axial strain of coronary arteries, however, isunknown. Therefore, the aim of this study is todetermine the physiological axial strain of theporcine left anterior descending coronary artery(LAD). Based on Weizscker (1983) and Schulze-Bauer (2003) it was hypothesized that: The in vivoaxial strain of an artery is the strain at which theaxial force (Fax) is relatively insensitive to changesin pressure (P). This physiological strain (fig.1,right, red line) was determined in an organ culturemodel. To test the hypothesis an isolated beatingheart experiment, in which a porcine heart is loadedphysiologically, was performed. Due to thepumping of the heart, a cyclic axial strain isinduced to the coronaries.