Diagnosis

The definitive diagnosis for bacterial endocarditis can be obtained by:

1. Echocardiographic evidence of vegetative valvular endocarditis along with a positive blood culture.

A presumptive diagnosis of bacterial endocarditis can be made by:

1. The development of a new heart murmur.
2. Evidence of septic or immune joint disease.
3. A positive blood culture.

Results of diagnostic tests:

1. Radiology:

• Will likely be normal
• There may be marked LAE and/or LVE
• Evidence of heart failure would be unusual unless aortic valve insufficiency is present or a ruptured chordae tendinae results in fulminate mitral valve insufficiency.

2. ECG may show:

• Ventricular ectopy
• Heart block
• Aberrant conduction

3. Blood Work may show:

• Positive blood culture in 1/3 of cases
• Leukocytosis with left shift and toxic changes
• May see evidence of kidney disease

4. Echocardiography may show:

• Vegetative lesion on the mitral valve and/or aortic valve
• Mitral regurgitation
• Aortic valve regurgitation
• There may be marked LAE and/or LVE

5. Other tests:

• Positive blood culture – 81%
• Positive urine culture
• Immune joint aspirate cytology
• Septic joint

Comment:

1. Aortic valve regurgitation or mitral valve regurgitation can occur due to destruction and perforation of valve leaflets.
2. Valvular disease can result in cardiac dysfunction and heart failure
3. Septic emboli can result in:
   – myocarditis
   – glomerulonephritis
   – arthritis