Long-term prognosis of rheumatic fever patients receiving regular intramuscular benzathine penicillin.

The prognosis for 115 rheumatic fever patients subsequently receiving regular intramuscular penicillin prophylaxis for at least 5 years was studied. Average follow-up was 9.3 years, and 57 patients were followed for 10 years or longer. Of the 79 patients with acute mitral regurgitation, 70% lost their murmur from 4 days to 8.5 years after it was first heard. This is in contrast to those with acute aortic regurgitation which persisted in 73%. No patient developed mitral or aortic stenosis: this suggests that regular prophylaxis may prevent the development of stenosis. Congestive failure, cardiomegaly, and arrhythmia correlated closely with persistence of murmurs, but increased P-R interval, acute QRS or T-voltage variation or both, and ST-T abnormalities did not.