Characterizing ventricular mechanics and energetics following
repeated coronary microembolization.
Todaka, Koji, David Leibowitz, Shunichi Homma, Peter Fisher, Carolyn
Derosa, Richard Stennett, Milton Packer, and Daniel Burkhoff.
Division of Circulatory Physiology, Division of Cardiology,
Department of Medicine; Department of Pathology; Department of
Surgery; Department of Anesthesiology; College of Physicians &
Surgeons, Columbia University, New York, NY 10032
APStracts 3:0318H, 1996.
Myocardial mechanics and energetics were investigated in an animal
model of moderate heart failure (CHF) created by repeated coronary
microembolizations in 6 dogs. The final fractional area change was
34+/-4%. Hearts of these animals were isolated, cross-perfused and
balloons placed in the LV. Chamber contractile state was markedly
depressed in embolized hearts as assessed by the slope (Ees: 2.74+/
-0.49 vs. 4.00+/-1.18mmHg/ml, p<0.01), and volume axis intercept
(V0: 8.7+/-5.9 vs. 1.0+/-3.2ml, p<0.01) of end-systolic
pressure-volume relation compared to a group of 6 normal dogs. The
end-diastolic pressure-volume relation of embolized hearts was
shifted to the right, indicating a dilation of the LV. However,
systolic and diastolic stress-strain relationships were similar in
the two groups, suggesting that the average myocardial properties of
the embolized hearts are similar to those of normal hearts. The
relationship between oxygen consumption and pressure-volume area in
embolized hearts had smaller intercept (2.98+/-0.44 vs. 3.92+/-0.39
x10-2mlO2/beat/100gLV, p<0.01) compared with the control group
with no change in the slope. These results contrast with previous
findings in pacing CHF and serve as an important characterization of
ventricular properties in this model of CHF from different etiology.
Received 15 September 1995; accepted in final form 2 July 1996.
APS Manuscript Number H873-5.
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