Infective Endocarditis

Cardiology / Infectious Disease

Overview

Definition

An infection of the endocardial surface of the heart, most commonly affecting the heart valves.

Epidemiology

High morbidity and mortality. Risk factors include IV drug use, prosthetic valves, and congenital heart disease.

Etiology & Risk Factors

  • Staphylococcus aureus (most common, acute, IVDU)
  • Viridans group Streptococci (subacute, dental procedures)
  • Enterococcus
  • HACEK organisms

Clinical Symptoms

  • Fever (most common)
  • New or changing heart murmur
  • Fatigue / Weight loss
  • Peripheral stigmata: Osler nodes (painful), Janeway lesions (painless), Roth spots, Splinter hemorrhages

Clinical Approach

Diagnosis

  • Modified Duke Criteria (Major and Minor criteria)
  • Blood Cultures (3 sets from different sites before antibiotics)
  • Echocardiogram (TTE initially, TEE is much more sensitive for vegetations)

Management

  • Prolonged IV antibiotics (4-6 weeks) based on culture results (e.g., Vanco/Ceftriaxone empirically)
  • Early cardiac surgery (valve replacement) if: heart failure, persistent infection, large vegetation (>10mm) with embolic event, or fungal etiology

Complications

  • Valvular destruction / severe regurgitation
  • Septic emboli (stroke, pulmonary infarcts)
  • Myocardial abscess