Endocarditis in the ED: Murmurs and Mayhem

-Case- 

A 45-year-old man with a history of IV drug use presents to the ED with persistent fevers, night sweats, and malaise over the past two weeks. He mentions some weight loss and recently noticed painful nodules on his fingertips. On exam, he has a new systolic murmur that wasn’t documented in previous visits. 

-Evaluation-

Endocarditis is a serious infection of the heart valves, often caused by bacteria (most commonly Staph aureus or Strep species) that form vegetations on the endocardial surface.

• Risk Factors:
  • IV drug use (tricuspid valve involvement more common)
  • Prosthetic heart valves, congenital heart disease
  • Recent dental procedures or poor dentition
  • Immunosuppression
• Classic Clinical Clues:
  • Fever + New Murmur → think endocarditis until proven otherwise!
  • Vascular embolic phenomena: splinter hemorrhages, Janeway lesions (painless macules on palms/soles), stroke, renal infarcts
  • Immunologic Findings: Osler nodes (painful fingertip nodules), Roth spots (retinal hemorrhages)
  • Septic Emboli: IV drug users often present with septic pulmonary emboli from right-sided endocarditis
• Familiarize yourself with Duke Criteria! Generally, you need to meet 2 major criteria, 1 major + 3 minor, or 5 minor criteria to appropriately diagnose endocarditis

-Management-

Treatment involves IV antibiotics and, in some cases, surgery for valve complications.

• Empiric antibiotics (before cultures return):
  • Native valve endocarditis: vancomycin + ceftriaxone
  • Prosthetic valve endocarditis: vancomycin + gentamicin + rifampin (for biofilm coverage)
• When to Call Surgery:
  • Large vegetations (>10mm) with embolization risk
  • Valve dysfunction causing heart failure
  • Abscess formation or prosthetic valve involvement
  • Persistent bacteremia despite antibiotics

-Fast Facts-

• Tricuspid valve involvement = IV Drug Use; mitral/aortic valve involvement = Non-IVDU causes
• Fever + murmur is endocarditis until proven otherwise
• Get blood cultures BEFORE antibiotics (3 sets from different sites)
• Echocardiogram (TEE > TTE) for Diagnosis

Endocarditis is a diagnosis that requires vigilance – miss it, and patients can suffer devastating complications. Recognize red flags early: fever, murmur, embolic findings, and IV drug use history. Early blood cultures, imaging, and targeted antibiotics can make the difference between life and death. 

Want to learn more? Read our in-depth study guide and listen to our podcast episode on this topic!

Cheers,

Tamir Zitelny, MD