Myocardial Lesions in Subacute Bacterial Endocarditis

Abstract

In a previous communication 1 rheumatic changes in the myocardium of children dying from subacute bacterial endocarditis were reported. Because of the fact that various other changes in the myocardium were observed during this study it seemed of interest to examine the hearts of a large group of patients, both adults and children, dying from subacute bacterial endocarditis, with special reference to myocardial changes. This seemed the more worth while in view of the discrepancy of opinions as to myocardial changes in subacute bacterial endocarditis. While Blumer 2 and others stated that the myocardium in subacute bacterial endocarditis is only rarely involved Clawson,3'4 Libman,5'6'7 and others emphasized the frequent occurrence of myocardial lesions.In the following, a short abstract of the more important pertinent literature is given and the results of a study of the myocardium of thirty-five hearts of patients dying from subacute bacterial endocarditis are reported. LITERATUREMurray8 in I922 noted that earlyin an attack of subacute bacterial endocarditis the heart muscle shows little response to the infective processes and the patient shows no evidence of cardiac failure.Blumer 2 in 1923 stated that the relatively slight involvement of the myocardium is a special peculiarity of subacute bacterial endocarditis. In I50 autopsies he reported, conditions of the myocardium were mentioned only thirty times. In twelve instances the recorded lesion was an evidence of toxemia, such as generalized fatty degeneration or cloudy swelling. Chronic interstitial myocarditis was noted eight times, acute myocarditis twice, small abscesses in the heart muscle three times, focal necrosis twice and infarcts twice.