AJP - Heart and Circulatory Physiology, Vol 235, Issue 6 767-H775, Copyright © 1978 by American Physiological Society
Ventricular performance and myocardial water content during hemodilution in dogs
G. A. Geffin, M. A. Vasu, D. D. O'Keefe, D. G. Pennington, A. J. Erdmann 3rd, E. Lowenstein, W. J. Powell Jr and W. M. Daggett
In dogs anesthetized with chloralose-urethan on right heart bypass, left
ventricular (LV) performance was assessed at constant LV stroke work before
and for up to 2.5 h after crystalloid hemodilution was established.
Lowering the hematocrit from 43.3 +/- 1.3% to 13.6 +/- 1.7% (SE) did not
significantly change LV end-diastolic pressure (LVEDP) initially. After 80
min LVEDP increased slightly by 1.7 +/- 0.6 cmH2O (P less than 0.05) at a
stroke work of 17.3 +/- 2.3 g.m. The value of dP/dt did not change
significantly throughout. When LV function curves were generated by
increasing cardiac output, the stroke work attained at an LVEDP of 10 cmH2O
decreased with hemodilution from 23.9 +/- 3.5 to 20.8 +/- 3.9 g.m (NS). LV
wall water content increased with hemodilution, from which it could be
calculated that there was an 18.6% increase in LV mass. Thus, despite an
increase in LV external girth demonstrated by LV circumferential gauges, it
is possible that increased wall thickness due to the water gain resulted in
little change or an actual decrease in LV end-diastolic volume. Thus,
profound hemodilution can be attained with only slight depression of LV
performance.
