Static Elastic Properties of the Left Coronary Circumflex Artery and the Common Carotid Artery in Dogs

Abstract

Static elastic properties were studied in isolated segments of the left coronary circumflex artery (LCCA) and the right common carotid artery (CA) from 14 dogs at in-vivo values of pressure and length. A microscope with a Filar micrometer was used to measure radius and length. From these data it was possible to study the pressure-radius relationship and compute various anisotropic elastic moduli as well as the strain energy density (SED). Results indicate: (1) Both arteries exhibited hysteresis which could be minimized within two inflation-deflation cycles. (2) The pressure-radius relationship at constant length was essentially linear over a pressure range corresponding to the in-vivo pulse pressure. (3) The value of volume distensibility was 3.4 x 10^-6 cm²/dyne for LCCA and 1.5 x 10^-6 cm²/dyne for CA. (4) LCCA was more distensible than CA in the circumferential direction. (5) LCCA was stiffer in the longitudinal direction than in the circumferential direction; the reverse was true of CA. (6) SED values at physiologic dimensions were 314 x 10³ dyne/cm² for LCCA and 226 x 10³ dyne/cm² for CA. These values could be reproduced within 6% when the loading procedure was altered.