Journal of Applied Physiology, Vol 52, Issue 1 254-259, Copyright © 1982 by American Physiological Society
Influence of the right ventricle on canine left ventricular function with PEEP
S. M. Scharf and R. Brown
In anesthetized dogs we evaluated the influence of increased right
ventricular (RV) pressures on left ventricular (LV) function by comparing
the hemodynamic effects of increases in RV afterload (pulmonary arterial
pressure) produced by positive end-expiratory pressure (PEEP) with those
due to pulmonary arterial occlusion (PAO). Left atrial (Pla) and right
atrial (Pra) pressures increased with PEEP and PAO [for Pla: 3.1 +/- 0.7
Torr (PEEP), 2.4 +/- 0.9 Torr (PAO); for Pra: 2.9 +/- 0.4 Torr (PEEP), 3.1
+/- 1.2 Torr (PAO)]. RV septal-free wall dimension (RVD) increased, and LV
septal-posterolateral dimension (L2) decreased with both conditions
[increases in RVD: 1.9 +/- 0.3 mm (PEEP), 2.2 +/- 0.5 mm (PAO); decrease in
L2: 1.1 +/- 0.4 mm (PEEP), 0.9 +/- 0.3 mm (PAO)]. Extracorporeal bypass of
the great veins did not alter these findings. LV function curves showed
less stroke work at any Pla during PEEP, this being unaffected by vagotomy.
When the RV was bypassed, there were no PEEP or PAO related changes in Pla
or LV function. Thus diminished LV function with PEEP is probably due to
the influence on the LV of a stressed RV in this situation.
