Journal of Applied Physiology, Vol 39, Issue 6 879-884, Copyright © 1975 by American Physiological Society
Influence of acute hypertension on aortic valve competence
N. O. Fowler, J. C. Holmes and H. Spitz
The effect of acutely induced hypertension on aortic valve competence was
studied in anesthetized dogs. Aortic pressure was increased by infusion of
methoxamine or mechanically; aortic valve competence was evaluated by
aortogrphy and by indicator dye. The aortic valve was normally competent;
aortic insufficiency appeared with increase of mean pressure by as little
as 20-50 mmHg; 6 of 9 animals showed aortic incompetence when mean aortic
pressure was elevated 45-70 mmHg, but the valve remained competent in 2 of
9 animals with mean pressure increments of 60-90 mmHg. The aortic root was
appreciably less distensible than was the proximal descending aorta; this
factor may limit the degree of aortic insufficiency in response to acute
hypertension in the dog.
