infective endocarditis

Question 1

what is infective endocarditis?

Answer 1

It is an inflammation of the endocardium (inner surface of the heart), usually of the valve(s)

Question 2

what organisms cause it?

Answer 2

Staphylococcus Aureus (most common) (in IVDA),

Streptococcus Viridans (due to valvular damage).

Question 3

which part of the heart is mostly affected?

Answer 3

In Infective Endocarditis, it is the Tricuspid Valve that is mostly affected, due to IVDA

Question 4

what are the risk factors and complications?

Answer 4

Risk factors:
Previous infective endocarditis

IVDU

Rheumatic Valve Disease

Complications:
Stroke

Renal Failure

Congestive Heart Failure

Valve Regurgitation

Vegetation (septic emboli)

Question 5

what are the symptoms and signs?

Answer 5

main presentation = Fever + New Murmur

Janeway Lesions

Osler’s Nodes

Roth Spots

Finger Clubbing

Anaemia

Night Sweats

Splinter Haemorrhages

Splenomegaly

Malaise

MSK Pain

Weight Loss

Vasculitis

Question 5

what 7 investigations are used?

Answer 5

Duke Criteria

Blood Cultures - 3 sets (6 bottles) taken over 24 hours at the peak of fever (to make a microbiological diagnosis) - 85/90% are diagnosed from the first two sets taken

Blood Tests - check U&E, ESR, CRP, FBC

CXR (check for cardiomegaly)ECG (check for a long PR interval) - check at regular intervals

ECHO (may show vegetation) - transthoracic echo

Urinalysis (to check for microscopic haematuria)

(Whilst awaiting blood cultures, Transthoracic Echo is the first line of investigation)

Question 5

what are the treatments used?

Answer 5

Antibiotics (for 4-6weeks):

• If native valve; Amoxycillin
• If prosthetic valve; Rifampicin, Gentamicin, Vancomycin

(Give IV Antibiotics for two weeks, then Oral Antibiotics for two to four weeks)

Surgery