Lecture on Endocarditis

Introduction

• Topic: Endocarditis
• Format: Dedicated video due to the complexity and importance for PANCE exam
• Additional Resources: Podcast available on Apple Podcasts and Spotify

Definition

• Infectious Endocarditis: Infection of the endocardial surface of the heart
  • Often affects one or more native heart valves
  • Can also involve prosthetic valves and intracardiac devices

Commonly Affected Valves

• Mitral Valve: Most commonly affected
• Tricuspid Valve: Most common in IV drug users (90% of right-sided cases)

Risk Factors

• Age > 60
• Male gender predominance (3:2 ratio)
• IV drug use
• Dentition or dental infections
• Structural heart disease or valvular heart disease
• History of infectious endocarditis
• Presence of prosthetic heart valves

Types of Endocarditis

Acute Bacterial Endocarditis

• Characteristics: Affects normal healthy valves
• Common Organism: Staphylococcus aureus
• Onset: Sudden (hours to days)

Subacute Bacterial Endocarditis

• Characteristics: Affects damaged or abnormal valves
• Common Organism: Streptococcus viridans
• Onset: Slow, insidious (can take months)

IV Drug Use Related Endocarditis

• Common Organism: Staphylococcus aureus (MRSA)
• Common Valve: Tricuspid

Prosthetic Valve Endocarditis

• Early: < 60 days from implantation
• Late: > 60 days from implantation
• Common Organism: Staphylococcus epidermidis

Organisms and Mnemonics

• Staphylococcus aureus: Acute, Addiction
• Streptococcus viridans: Vulnerable valves
• Staphylococcus epidermidis: Enterous Prosthetic Implants
• Enterococcus: GI/GU procedures (Enema, TURP)
• Streptococcus bovis: Bowel (colon cancer, ulcerative colitis)

Clinical Manifestations

• Common Symptoms: Fever, constitutional symptoms (night sweats, fatigue, myalgias)
• Other Symptoms:
  • Murmurs (new or worsening)
  • Janeway lesions (painless)
  • Osler nodes (painful)
  • Roth spots (retinal lesions)
  • Splinter hemorrhages (nail beds)

Mnemonic for Symptoms

• "I got endocarditis from JANE": Fever, Roth spots, Osler nodes, Murmur, Janeway lesions, Anemia, Nail bed hemorrhages, Emboli

Diagnosis Criteria

• Modified Duke Criteria:
  • Major:
    • Two positive blood cultures
    • Evidence of endocardial involvement on echo
  • Minor: Clinical symptoms, positive echo or culture not meeting major criteria, predisposing factors

Treatment

• Multidisciplinary Care: Involvement of infectious disease, cardiology, cardiac surgery
• Empiric Antibiotic Therapy:
  • Native Valves: Anti-staphylococcal penicillin (nafcillin, oxacillin) + ceftriaxone/gentamicin
  • Prosthetic Valves: Vancomycin, gentamicin, rifampin
  • Fungal: Amphotericin B

Antibiotic Mnemonics

• Native Valves: "Only Native Cardiac Gears" - Oxacillin, Nafcillin, Ceftriaxone, Gentamicin
• Prosthetic Valves: "Valves Generally Repaired" - Vancomycin, Gentamicin, Rifampin

Antibiotic Prophylaxis

• When Needed: High risk of adverse outcomes if endocarditis occurs
• Procedures: Dental procedures, respiratory tract procedures (with biopsy), skin or soft tissue procedures
• Preferred Antibiotic: Amoxicillin (2g prior to procedure)
• Alternative for Allergy: Clindamycin

Key Takeaways

• Remember mnemonics for organisms and symptoms
• Understand diagnosis criteria and treatment options
• Know when and how to apply antibiotic prophylaxis

This summary captures essential information needed for understanding endocarditis, particularly for PANCE preparation. Always use mnemonics and key points to efficiently recall critical details.