abo and rh blood groups were studied in a total of 1680 patients with cardiovascular diseases (congenital n=547, valvular n=887 and coronary n=246). statistical analysis (x2and woolf’s test) showed significant excess of b/o in mitral valve, aortic valve total valvular diseases and heart diseases generally, also an increase of a/o in myocardial infarction. significant increase of the frequency o...