AJP - Heart and Circulatory Physiology, Vol 258, Issue 4 1208-H1215, Copyright © 1990 by American Physiological Society
LV pressure-volume area and oxygen consumption: evaluation in intact dog by fast CT
N. Chung, X. Wu, K. R. Bailey and E. L. Ritman
Department of Physiology and Biophysics, Mayo Medical School, Rochester, Minnesota 55905.
The relationship between left ventricular (LV) myocardial oxygen
consumption (MVO2) and LV systolic pressure-volume area (PVA) was
investigated in anesthetized closed-chest dogs with intact reflexes and
subsequently with beta-adrenergic blockade, with or without simultaneous
muscarinic blockade. LV chamber volumes were measured using a fast
computerized tomography (CT) scanner (dynamic spatial reconstructor, DSR)
at 33-ms intervals. Myocardial blood flow was measured from the DSR scans
of aortic root angiograms. With intact reflexes, LV MVO2 (Y) related to PVA
(X) values as Y = (4.28 +/- 1.81)X + (1.94 +/- 6.0) (n = 24)
(mJ.g-1.cycle-1). With beta-adrenergic blockade, LV MVO2 (Y) related to PVA
(X) value as Y = (4.24 +/- 1.03)X - (6.43 +/- 6.5), (n = 9)
(mJ.g-1.cycle-1). With beta-adrenergic and muscarinic blockade, LV MVO2 (Y)
related to PVA (X) value as Y = (2.84 +/- 1.72)X + (3.51 +/- 5.15), (n =
13) (mJ.g-1.cycle-1). The slopes of these regressions are higher than the
slopes demonstrated by others in isolated ventricles but very similar to
those demonstrated in open-chest dogs.
