[Cardiac and circulatory physiological studies in cattle with and without cardiomyopathy].

Cardiovascular examinations were performed on 29 Red-Holstein-Simmental cows, suffering from cardiomyopathy. We compared the results with those from 18 healthy animals. The cows with cardiomyopathy showed a higher heart rate, a higher and broader P-wave, a prolongation of the electric systole in relation to the RR-Intervall, an increased systolic and diastolic pressure in the right ventricle and in the pulmonary artery, a higher peak pressure rise in the right ventricle and a lower peak pressure rise in the left ventricle with lower systolic and higher diastolic pressure. A lower oxygen content in the right-ventricular blood and lower carbon dioxide content in the left-ventricular blood of the sick cows may be due to a longer circulation time. The observed pulmonary hypertension is probably the result of the left heart insufficiency and is being discussed with regard of the histopathological alterations in the heart muscle and the pulmonary vessels. Possible reasons for the cardiomyopathy are described and evaluated.