The effect of myocardial swelling on the residual strain in the
left ventricle of the rat.
Y., Lanir, Hayam, G., Abovsky, M., Zlotnick, A. Y., Uretzky, G., Nevo,
E., Ben-Haim, S. A.
The Julius Silver Institute of Biomedical Sciences, Dept. of
Biomedical Engineering, Bruce Rappaport Faculty of Medicine, The
Rappaport Institute for Research in the Medical Sciences, Department
of Cardiothoracic Surgery, Carmel Hospital, Haifa and Bruce Rappaport
Faculty of Medicine, Technion Entrepreneurial Incubator Company,
Technion - Israel Institute of Technology, Haifa 32000, Israel
APStracts 2:0558H, 1995.
Left ventricular (LV) residual strain in the unloaded state, was shown
previously to affect the LV performance. The interrelationship
between myocardial swelling and LV residual strain were studied, both
experimentally and theoretically. Myocardial swelling was induced by
retrograde perfusion of the beating, non-working, isolated rat hearts
with perfusate of graded osmolarities (200 to 420 mOsm). The opening
angle (an index of residual strain), in radially cut equatorial
cross-sectional slices, and their water content, were measured in
forty arrested rat left ventricles. Both water content and opening
angle decreased significantly with osmolarity from 84.2+/-0.45% and
77.2+/-9.2 degrees at 200 mOsm to 76.5+/-1.05% and 36.3+/-9.8 degrees
at 420 mOsm (p<0.001 respectively). A morphologically based
theoretical model was developed and yielded a swelling - residual
strain relationship, which agrees well with the data. Our results
indicate that myocardial swelling is strongly related to LV residual
strain, suggesting that swelling, through its effect on residual
strain, can affect both the LV function and its adaptation to varying
loading conditions.
Received 14 July 1995; accepted in final form 7 November 1995.
APS Manuscript Number H658-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 December 95