title: Influence of acute hypertension on aortic valve competence.
abstract: 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.
mesh_terms: D000818:Animals; D001021:Aortic Valve / Q000503:physiopathology*; D001022:Aortic Valve Insufficiency / Q000209:etiology; D004285:Dogs; D004395:Dye Dilution Technique; D006339:Heart Rate; D006973:Hypertension / Q000503:physiopathology*; D008729:Methoxamine / Q000494:pharmacology; D008943:Mitral Valve / Q000503:physiopathology
chemical_list: D008729:Methoxamine