Synopsis
Recognise native-valve infective endocarditis, preserve blood-culture yield, sequence echocardiography and coordinate prolonged directed therapy with timely surgery and embolic assessment.
- Suspect infective endocarditis with persistent fever plus a murmur, embolic event, vascular or immune phenomenon, risk valve or unexplained bacteraemia.
- In a stable adult, obtain three correctly filled peripheral blood-culture sets from separate venepunctures before any antibiotic.
- Do not wait for the full sampling sequence in septic shock; collect cultures rapidly and start intravenous treatment.
- TTE is the first echocardiographic test, while TOE follows when TTE is negative or inadequate but suspicion remains high or complications need definition.
- A normal early echocardiogram does not exclude endocarditis; repeat imaging is required when clinical probability remains high.
- Apply Duke or contemporary diagnostic criteria as a framework, not a replacement for endocarditis-team judgment.
- Antibiotic choice and duration are organism-, valve-, renal- and complication-specific and should be prescribed with infection specialists from susceptibility.
- Surgery is time critical for heart failure, uncontrolled infection, abscess, difficult organisms and selected embolic-risk vegetations.
Key red flags
New severe regurgitation with pulmonary oedema or cardiogenic shock requires emergency valve-surgery assessment.
Persistent fever or positive cultures despite active therapy suggests abscess, resistant organism or uncontrolled focus.
New PR prolongation or atrioventricular block can indicate peri-annular extension and abscess.
Acute focal neurological deficit may be embolic infarction, haemorrhage or infected aneurysm and changes surgical timing.
Severe back pain, hot joint or focal limb pain may represent metastatic vertebral, joint or arterial infection.
Staphylococcus aureus bacteraemia is never dismissed as contamination and requires endocarditis assessment.
A new regurgitant murmur, heart-failure signs or pulmonary oedema supports valve destruction, although absence of a murmur does not exclude disease.
Stroke, splenic or renal infarction, acute limb ischaemia, pulmonary embolic nodules in right-sided disease or focal pain may reveal endocarditis.
Staphylococcus aureus, enterococcal or persistent bacteraemia, injection exposure, haemodialysis and recent invasive infection greatly increase pre-test probability.
Investigation priorities
Recover the organism and susceptibility before antimicrobial exposure in a stable patient.
Management branches
Endocarditis is suspected and the patient is haemodynamically stable without immediate organ-threatening sepsis.
- Take three peripheral blood-culture sets from separate venepunctures before any antibiotic and document every recent antimicrobial dose.
- Perform TTE promptly, ECG, renal and liver assessment, urinalysis and focused examination for heart failure, emboli, portals and metastatic infection.
- Contact cardiology and infection specialists at diagnosis suspicion rather than waiting for all criteria to accumulate.
- If cultures remain negative, review antibiotic exposure and use exposure-directed serology, molecular testing and planned deep or valve tissue studies.