Key Points
- Use the highest‑yield diagnostic test early; do not let testing delay time‑critical therapy.
- Set objective targets and reassess frequently.
- Plan definitive source control or disease‑specific therapy when indicated; document follow‑up and patient education.
Algorithm
- Draw 3 sets of blood cultures; start empiric therapy when unstable or after draws when stable.
- Perform TTE → TEE; apply Duke criteria.
- Identify surgical indications; tailor antibiotics to organism and valve; monitor for complications.
Clinical Synopsis & Reasoning
Suspect with fever and new murmur, embolic phenomena, or positive blood cultures. Obtain 3 sets of blood cultures before antibiotics when feasible; use Duke criteria for diagnosis. Start empiric therapy based on native vs prosthetic valve and tailor to cultures; identify indications for surgery (heart failure, uncontrolled infection, embolic risk).
Treatment Strategy & Disposition
Stabilize ABCs. Initiate guideline‑concordant first‑line therapy with precise dosing and continuous monitoring. Escalate to advanced/procedural interventions based on explicit failure criteria. Define ICU, step‑down, and ward disposition triggers; involve specialty teams early.
Epidemiology / Risk Factors
- Risk varies by comorbidity and precipitants; see citations for condition‑specific data.
Investigations
| Test | Role / Rationale | Typical Findings | Notes |
|---|
| Blood cultures ×3 from separate sites | Diagnosis | Pathogen ID | Before antibiotics if stable |
| Transthoracic → Transesophageal echo | Imaging | Vegetations/abscess | TEE more sensitive |
| Inflammatory markers and imaging for emboli (CT/MRI as indicated) | Complications | Septic emboli, mycotic aneurysm | — |
High-Risk & Disposition Triggers
| Trigger | Why it matters | Action |
|---|
| Heart failure from valve dysfunction | Leading cause of death | Urgent surgery consult |
| Uncontrolled infection/abscess or persistent bacteremia | Medical failure | Surgery indicated |
| Embolic events or large vegetations (≥10 mm) | Stroke/embolism risk | Early surgery consideration |
| Prosthetic valve or device infection | Complex infections | Multidisciplinary team; surgery likely |
| Neurologic complications (ICH, stroke) | Timing of surgery impacted | Neuroimaging; team decision |
Pharmacology
| Medication/Intervention | Mechanism | Onset | Role in Therapy | Limitations |
|---|
| Empiric: Vancomycin + Cefepime (native) or add Rifampin/Gentamicin (prosthetic, early) | Antibiotics | Hours | Cover MRSA, streptococci, enterococci | Tailor to cultures/valve type |
| Surgical consultation early | Definitive control | Hours-days | HF, abscess, persistent bacteremia, large vegetations | Multidisciplinary endocarditis team |
| Anticoagulation management (prosthetic/AF) | Safety | Balance embolic vs bleed risk | Hold in acute cerebral hemorrhage |
Prognosis / Complications
- Outcome depends on timeliness of diagnosis and definitive therapy; monitor for complications.
Patient Education / Counseling
- Provide red‑flag education, adherence guidance, and explicit return precautions; arrange timely specialty follow‑up.
References
- AHA/IDSA guideline on infective endocarditis — Link