LV pressure-volume area and oxygen consumption: evaluation in intact dog by fast CT.
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.
Chung
N
N
Department of Physiology and Biophysics, Mayo Medical School, Rochester, Minnesota 55905.
Wu
X
X
Bailey
K R
KR
Ritman
E L
EL
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001341:Autonomic Nervous System / Q000502:physiology; D001794:Blood Pressure; D001810:Blood Volume; D004285:Dogs; D006321:Heart / Q000000981:diagnostic imaging / Q000502:physiology*; D006352:Heart Ventricles; D009116:Muscarine / Q000037:antagonists & inhibitors; D009206:Myocardium / Q000378:metabolism*; D010101:Oxygen Consumption; D012018:Reflex / Q000502:physiology; D012044:Regression Analysis; D013997:Time Factors; D014057:Tomography, X-Ray Computed
D000319:Adrenergic beta-Antagonists; D009116:Muscarine