The clinical situation in which fever and valvular heart disease coexist presents a problem in differential diagnosis and management which is quite different from that associated with either condition alone. The causes of fever more or less peculiar to valvular heart disease are active rheumatic fever, bacterial endocarditis, drug fever, embolism, congestive heart failure, hemoglobin pneumonia, systemic lupus erythematosus, and atrial myxoma or thrombus. Bacterial endocarditis should be given first consideration when fever and heart murmur coexist.
Ross RS, McKusick VA, Harvey JC. THE PROBLEM OF FEVER IN PATIENTS WITH VALVULAR HEART DISEASE. JAMA. 1957;165(1):1-7. doi:10.1001/jama.1957.02980190003001