AJP - Heart and Circulatory Physiology, Vol 253, Issue 5 1298-H1304, Copyright © 1987 by American Physiological Society
Cardiac output in adult and neonatal rats utilizing impedance cardiography
R. W. Gotshall, J. C. Breay-Pilcher and B. D. Boelcskevy
Department of Physiology and Biophysics, School of Medicine, Wright State University, Dayton 45435.
Impedance cardiography (IC) has the potential to be applied to very small
animals for the measurement of cardiac output (Q). To evaluate this, Q
measured by impedance (ZQ) and thermal dilution (TDQ) were compared in
adult Sprague-Dawley rats. Absolute values for TDQ were comparable with ZQ
(e.g., 29.7 vs. 26.0 ml.min-1.100 g-1), and both equally followed the
change in Q caused by hemorrhage and reinfusion of blood. IC was also
evaluated in neonatal rats (1 and 7 day old). Control ZQ values were 113
ml.min-1.100 g-1 for the 1-day-old rats, and 104 ml.min-1.100 g-1 for
7-day-old rats. Both stroke volume and Q decreased with head-up tilt and
increased with head-down tilt for both ages. Therefore, in the neonate, ZQ
decreased appropriately with age and with preload reduction. From these
results, it is concluded that IC can be utilized to evaluate cardiac
function in neonatal and adult rats.
