Validation of different methods to compare isovolumic cardiac
function in isolated hearts of varying sizes.
Str[diaeresis]omer, Hinrik, Antonio Cittadini, Grazyna Szymanska, Carl
S. Apstein, and James P. Morgan.
Charles A. Dana Research Institute and the Harvard-Thorndike
Laboratory, Cardiovascular Division, Department of Medicine, Beth
Israel Hospital, Harvard Medical School and the Cardiac Muscle
Research Laboratory, Whitaker Cardiovascular Institute, Boston
University School of Medicine, Boston, Massachusetts 02215
APStracts 3:0322H, 1996.
Functional comparison of isolated hearts with different sizes has been
difficult because function varies at different ventricular volumes.
To date, no standard volume (Vol) has been established. In order to
determine the most accurate experimental approach, we tested 5
different methods to standardize Vol in control hearts with different
sizes but similar papillary muscle function and in hearts with
concentric hypertrophy: Vol = 120 [mu]l (M1), Vol at diastolic
pressure = 10 mmHg (M2) or diastolic wall stress = 4 kdyn/cm2 (M3),
Vol = 25 [mu]l/100g body weight (M4), Vol = 50% of Volmax (= volume
at peak developed pressure) (M5). Systolic and diastolic function of
control groups was different using M1, comparable using M2 or M5. M3
and M4 showed borderline significant differences. We concluded that
M5 and M2 were suitable to compare function among hearts of different
sizes. If diastolic compliance is of interest like in concentric
hypertrophy, parameter volume curves should be normalized by Volmax
to compare function at corresponding points of the Frank-Starling
curve (e.g. at 50% of Volmax = M5).
Received 21 December 1995; accepted in final form 8 July 1996.
APS Manuscript Number H1187-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 21 August 1996