Abstract
The present study was designed to present microscopic findings of various organs of the rabbits with aortic or pulmonic stenosis. The histological material available for this study consisted of sixty-one rabbits, four of which showed chronic congestive heart failure clinically or at autopsy. The duration of the experiment varied from 15 hr. to 495 days. The summary and conclusion of this study is as follows : 1. As the pathologic changes in the heart, hypertropy, atrophy or degeneration of the muscle fibers and myocardial fibrosis in many rabbits, and myocardial inflammatory lesions in some rabbits were found. But cardiac failure did develop in four rabbits without good correlation with the character, extent, or localization of these cardiac lesions. These pathologic changes were merely evidences of myocardial disease and could not be indicative of cardiac failure. The microscopic study of the heart did not reveal any characteristic lesions qualitatively nor quantitatively which could adequately account for the development of cardiac failure.2. In many rabbits with aortic stenosis the lungs showed venous congestion, edema and thickening of alveolar wall. Cardiac cirrhosis of the liver was found in two rabbits with pulmonic stenosis and partial cirrhosis, in one with aortic stenosis. Fibrosis of the spleen was found in one rabbits with pulmonic stenosis. The kidneys revealed little changes related with cardiac failure, except for a slight venous congestion.3. The results of the visible macroscopic and microscopic study of various organs indicate that the passive venous congestion is localized in the organs retrograde from the failing cardiac chamber and it is more striking in those organs proximal to that chamber, and that this congestion is already present even in the so-called "Stage of Incompensation".
