AJP - Heart and Circulatory Physiology, Vol 246, Issue 1 114-H119, Copyright © 1984 by American Physiological Society
Right and left ventricular pressure-volume response to positive end-expiratory pressure
W. P. Santamore, A. A. Bove and J. L. Heckman
Cardiovascular effects of positive end-expiratory pressure (PEEP) at 20
cmH2O were examined in six mongrel dogs (11.3-15.0 kg). The dogs were
anesthetized through a combination of intramuscular Innovar and gaseous
anesthesia (60% N2O-40% O2). For volume measurements, radiodense tantalum
screws were placed on the endocardial surface of the left and right
ventricle. Esophageal and left and right ventricular pressures were
measured. With the use of this preparation, the effects of positive
end-expiratory pressure (PEEP = 20 cmH2O) on cardiovascular function were
examined. PEEP caused right ventricular transmural pressures to decrease,
3.4 +/- 1.0 to 2.0 +/- 1.0 mmHg end-diastolic (P less than 0.05) and 29.2
+/- 2.2 to 27.9 + 2.2 mmHg peak systolic; left ventricular transmural
pressures decreased, 5.9 +/- 1.6 to 1.2 +/- 1.4 mmHg end-diastolic (P less
than 0.05) and 117.2 +/- 8.0 to 76.2 +/- 7.4 mmHg peak systolic (P less
than 0.05). After volume loading the animal (500 ml dextran), PEEP caused
similar changes in right and left ventricular pressures. Plots of
end-diastolic volume versus pressure showed an increase in the apparent
diastolic stiffness in both ventricles with decreased end-diastolic volume.
