Oxygen metabolism of the hypertrophic right ventricle in open chest dogs.
OBJECTIVE
The aim was to investigate oxygen metabolism of the hypertrophic right ventricle in anaesthetised open chest dogs.


METHODS
Right ventricular hypertrophy was induced by right ventricular pressure overload with banding the pulmonary artery for six months. Coronary blood flow and myocardial oxygen metabolism of the hypertrophic right ventricle were determined during control and after increasing right ventricular oxygen consumption, and compared with those of the normal right and left ventricles.


METHODS
Seven mongrel dogs with right ventricular hypertrophy and 21 normal dogs were used. All were anaesthetised with pentobarbitone sodium.


RESULTS
Oxygen extraction [(A-V)O2] of the hypertrophic right ventricular myocardium was greater than that of normal right ventricle in controls and almost identical to the (A-V)O2 of the normal left ventricle. It showed no increase when coronary blood flow and right ventricular oxygen consumption were raised in response to a further elevation of the right ventricular pressure and isoprenaline infusion. However, the right ventricular interventions which increased right ventricular oxygen consumption produced an elevation of (A-V)O2 of the right ventricle with an increase in right coronary blood flow.


CONCLUSIONS
Higher oxygen extraction during control and no response of oxygen extraction of the hypertrophied right ventricle in response to stimuli which increase right ventricular oxygen consumption indicate that oxygen supply to the hypertrophic right ventricle is different from that of the normal right ventricle, and is more like that of the left ventricle.
Saito
D
D
Department of Cardiovascular Medicine, Okayama University Medical School, Japan.
Tani
H
H
Kusachi
S
S
Uchida
S
S
Ohbayashi
N
N
Marutani
M
M
Maekawa
K
K
Tsuji
T
T
Haraoka
S
S
D000818:Animals; D006332:Cardiomegaly / Q000378:metabolism*; D003331:Coronary Vessels / Q000502:physiology; D004195:Disease Models, Animal; D004285:Dogs; D005260:Female; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology*; D012039:Regional Blood Flow / Q000187:drug effects
D007545:Isoproterenol