Abstract
We studied the occurrence of myocardial ischemia due to peripheral disturbances of coronary circulation using histological analyses and measurements of the cardiac function.
Measurements were taken for EDP, max dP/dt, max(—)dP/dt, blood pressure, pulse rate and left ventricular pressure in 10 rabbits before and after administration of a cholesterol diet for 3 months (chol rabbits), The same measurements were also taken in 5 normal rabbits. Counting was made of all the peripheral coronary arteries in diameter 50∼150 μm in which more than 75% of stenosis was observed by sectioning longitudinally every 5 mm and fibrosis % was also found.
In chol rabbits, EDP exhibited significant increases from 2.1±1.2 to 7.3±4.0 mmHg, and max(—)dP/dt exhibited significant decreases from 3, 955±583 mmHg to 3, 300±429 mmHg before and after the administration, respectively (p<0.05). No significant difference was observed in the other items, however. The main coronary artery exhibited stenosis in not more than 50% of either group, but in the chol rabbits, significant increases were observed both in the ratio of the number fo stenotic blood vessels (20.7%, 0.94%) and the fibrosis (2.71%, 1.66%).
In the chol rabbits, the increases in EDP and the decrease in max(—)dP/dt was pressumed to have resulted from peripheral coronary stenosis and associated fibrosis, and was considered to suggest the presence of myocardial ischemia.
