Endocarditis

Question 1

Definition

Answer 1

Inflammation of the heart valve, usually secondary to infection
Usually left-sided unless patient has a history of IV drug use in which case it is usually right-sided involving tricuspid valve

Common cause of “fever of unknown origin (FUO)”
Intravascular infection that can spread to other organs, must watch for signs of neurologic, joint, and lung manifestations

Question 2

Acute endocarditis caused by

Answer 2

Streptococcus pneumoniae
Streptococcus pyogenes
Neisseria gonorrhoeae
Staphylococcus aureus (especially in IV drug users)

Question 3

Subacute Bacterial Endocarditis caused by

Answer 3

slower onset of symptoms with less severe symptoms

Enterococcus: the source is typically from a cystoscopy in the
setting of a UTI
S. viridans: the source is typically an upper respiratory infection
Staphylococcus epidermidis: the source is typically the skin

Question 4

Murantic Endocarditis caused by

Answer 4

Due to metastatic cancer seeding to the valves
Commonly associated with cerebral infarcts due to malignant emboli
Very poor prognosis

Question 5

Libman-Stacks Endocarditis caused by

Answer 5

Systemic lupus erythematous (SLE), usually asymptomatic but murmur can be heard

Question 6

Risk Factors

Answer 6

History of RHD
Valvular heart disease
IV drug use
Immunosuppression
Prosthetic heart valve

Question 7

Symptoms

Answer 7

High fever lasting for weeks
Cough
Dyspnea
Systemic symptoms of weakness , fever and malaise

Question 8

Physical Exam

Answer 8

Heart auscultation usually reveals a murmur often mid-systolic of tricuspid regurgitation over LLSB

Osler’s nodules small, red-purple, tender nodules on fingers and toes;
immune-mediated small-vessel vasculities in response to long-standing micro-abscesses

Janeway lesions non-tender, dark macules on palms and soles, results from septic micro-embolisms

Roth spots retinal hemorrhages

Subungal petechiae (splinter hemorrhages)

Question 9

Evaluation

Answer 9

Diagnosis based on Duke Criteria (1994, revised 2000)

Blood cultures
Positive blood cultures drawn at least 12 hours apart or multiple positive cultures (at least 3 of 4) with the first and last drawn at least 1 hour apart

Echocardiography look for vegetations, negative echo does not rule out endocarditits

CXR may reveal septic emboli in right-sided endocarditits

Question 10

Differentials

Answer 10

Osteomyellits, abscess, pneumonia, rheumatic fever, prostatitis in males, STDs in
females, other causes of FUO

Question 11

Treatment

Answer 11

Empiric prolonged antibiotic therapy
treat for 4-6 weeks; recent evidence shows 2 weeks OK for certain organisms, tailor for organism based on cultures

Surgical valve replacement indicated in cases with worsening valve function, abscess formation or conduction disturbance (arrhythmia)

Question 12

Prognosis, Prevention, and Complications

Answer 12

Prognosis is good
May prevent secondary infection with prophylactic antibiotics (amoxicillin or erythromycin) before dental work
Complications occur secondary to embolic phenomena as described