Temporal evaluation of left ventricular remodeling and function in
rats with chronic volume overload.
Brower, Gregory L., Jeffrey R. Henegar, Joseph S. Janicki.
Department of Physiology and Pharmacology, Auburn University,
Auburn, Alabama, USA
APStracts 3:0223H, 1996.
The left ventricle (LV) significantly dilates and hypertrophies in
response to chronic volume overload. However, the temporal responses
in LV mass, volume, and systolic/diastolic function secondary to
chronic volume overload induced by infrarenal arteriovenous (AV)
fistula in rats have not been well characterized. To this end, LV end
diastolic pressure (EDP), size, and function (i.e., isovolumetric
pressure-volume relations in the blood perfused isolated heart) were
assessed at 1, 2, 3, 5, and 8 weeks post-AV fistula and compared to
age-matched controls. Progressive hypertrophy (192% at 8 weeks),
ventricular dilatation (172% at 8 weeks), and a decrease in
ventricular stiffness (257% at 8 weeks) occurred in the fistula
groups. LVEDP increased from a control value of 4.2 +/- 3.1 mm Hg to
a peak value of 15.7 +/- 3.6 mm Hg following three weeks of volume
overload. A subsequent decline in LVEDP to 11.0 +/- 6.0 mm Hg
together with further LV dilatation (169%) corresponded to a
significant decrease in LV stiffness (222%) at 5 weeks post-AV
fistula. Myocardial contractility, as assessed by the isovolumic
pressure-volume relationship, was significantly reduced in all AV
fistula groups, however, the compensatory remodeling induced by 8
weeks of chronic biventricular volume overload tended to preserve
systolic function.
Received 27 October 1995; accepted in final form 13 May 1996.
APS Manuscript Number H1006-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 June 96