Infective Endocarditis

Question 1

What is endocarditis?

Answer 1

• Microbial infection of endothelium lining the heart

Question 2

What are the risk factors for infective endocarditis?

Answer 2

• Valvular heart disease
• Rheumatic heart disease
• Congenital heart disease
• Artifical valves
• IV drug use
• Electronic pacemakers

Question 3

Briefly outline the pathogenesis behhind infective endocarditis.

Answer 3

• Damaged endothelium is thrombogenic and bacterial platelet aggregates (vegetations) develop
• Underlying conditions include calcified aortic valves and mitral valves with wear and tear changes
• Normal valves are not usually involved, but may be affected by highly virulent bacteria, particularly staphylococci

Question 4

How can infective endocarditis be categorised based on method of acquisition?

Answer 4

• Health-care associated IE – (Non) nosocomial
• Community acquired IE
• Intravenous drug abuse-associated IE

Question 5

How can infective endocarditis be categorised based on location?

Answer 5

• Left and right sided IE
• Device related IE
• Native valve and prosthetic valve IE (Early < 1 year after surgery or late >1 year after surgery)

Question 6

What are the most common causes of NVE in non IV drug users?

Answer 6

• Staph aureus (28%)
• Coagulase Negative Staph (9%)
• Streptococci (35%)
• Enterococci (11%)
• Gram negative (3%)
• Culture Negative ( 9%)