Journal of Applied Physiology, Vol 53, Issue 3 726-730, Copyright © 1982 by American Physiological Society
Statistical analysis of effect of anoxia on rate of change of ventricular pressure
C. George and M. T. Kopetzky
Hearts from 32 male Sprague-Dawley rats were studied to determine effects
of anoxia on ventricular contractility. Maximum rate of ventricular
pressure changes with time (Pmax) were obtained from simultaneous
recordings of right and left ventricular pressure curves. Peak aortic flow
and heart rate were measured. Anoxia was produced by 100% N2 respiration.
Statistical models were repeated-measures analysis of variance and
randomized block factorial analysis of variance. Alpha was 0.05. Heart rate
during anoxia was significantly lower than during the 1st min of recovery.
Heart rate during both these periods was significantly lower than in
preanoxia or the remainder of recovery. Peak aortic flow was not
significantly altered. In left ventricles positive Pmax was significantly
higher than negative Pmax. In right ventricles positive and negative Pmax
were not significantly different. Left ventricular Pmax was significantly
depressed during anoxia, whereas right ventricular Pmax was not.
Significant differences in pressure developed per mass of tissue was a
possible source of variation in right (0.12 +/- 0.002 mmHg/mg) and left
(0.16 +/- 0.009 mmHg/mg) ventricular contractile maintenance.
