-IBIS-1.5.0-
tx
cardiovascular system
subacute bacterial endocarditis
diagnoses

definition and etiology

definition:
bacterial infection of the endocardium or heart valves, recognized by systemic symptoms, tendency for embolism, and endocardial vegetations; also termed "bacterial endocarditis"

etiology:
The associated microorganism of SBE is typically alpha-hemolytic streptococcus, although other strep strains and staph aureus (especially in patients with prosthetic valves) are increasing in frequency as the cause. Bacteremia is often associated with infection following, oral cavity infections and operative procedures. Congenital or acquired malformed or damaged heart valves are highly susceptible to the disease. It is most common in people with preexisting valvular heart disease.

signs and symptoms

signs and symptoms:
onset is gradual; it is easy to misdiagnose as the systemic signs become prominent without any signs of cardiac involvement
• fever: usually below 102.2° F, and typically remittent
• chills (occasionally), malaise, arthralgia
• weakness, fatigue, weight loss, night sweats, anorexia
• embolic signs and symptoms: paralysis, chest pain, abdominal pain, painful fingers or toes, sudden blindness
• mucocutaneous lesions : petechiae in mouth, pharynx, or conjunctiva
• changed or new heart murmur
• splenomegaly
• Janeway's lesions: red macules on soles and palms
• Osler's nodes: tender nodules on the tips of the fingers and toes
• possible signs of CHF, in advanced cases

lab findings:
• anemia: normochromic, normocytic; rarely hemolysis
• microscopic hematuria
• (+) blood cultures in 80-90%
• leukocytosis
• increased globulins, resulting in increased ESR
• false (+) RF
• hematuria and albuminuria
• may see polyclonal gammopathy on protein ELP

course and prognosis

Conventional physicians recommend prophylactic antibiotics whenever "dirty surgery" is performed (e.g. dental or rectal procedures) on patients with damaged or prosthetic heart valves. Untreated SBE is fatal; even with antibiotic treatment, the mortality rate is 10% for strep, more for fungal or gram-negative endocarditis. Death can be a result of cachexia and anemia, embolic phenomenon of the cerebrum or lungs, or kidney failure. Valvular scarring and damage can lead to heart failure even after the disease has been successfully treated.

differential diagnosis

• other diseases as the systemic symptoms indicate
• rheumatic fever
• atrial myxoma


footnotes