AJP - Heart and Circulatory Physiology, Vol 253, Issue 1 75-H82, Copyright © 1987 by American Physiological Society
Biaxial mechanical properties of human pericardium and canine comparisons
M. C. Lee, Y. C. Fung, R. Shabetai and M. M. LeWinter
The two-dimensional mechanical properties of human pericardium from seven
males undergoing coronary artery bypass surgery were studied. A 25-mm
square piece of parietal pericardium overlying the right ventricle was
excised. An approximately 8-mm square target was marked at the center, and
its dimension was measured electrooptically. When immersed in physiological
saline at 37 degrees C, the specimen was subjected to biaxial isotropic
loading. Large deformations developed in the beginning of the loading; the
pericardium became increasingly stiffer when load was increased, and then
became almost inextensible. As in canine pericardium [Lee et al., Am. J.
Physiol. 249 (Heart Circ. Physiol. 18): H222-H230, 1985], hysteresis was
present and tension-stretch relationship was insensitive to loading
frequency during cyclic loading, relaxation of tension was substantial, and
creep was insignificant. Unlike canine specimens, however, human
pericardium was nearly isotropic and almost three times as thick [mean 0.55
+/- 0.02 mm (SD)]. The human tension-area relation for isotropic loading
could be described by an exponential function and was found to shift
significantly to the left of the canine. Therefore, human pericardium is
less extensible than canine.
