Endocarditis (infective)

Question 1

Endocarditis (infective): Definition

Answer 1

• Infective endocarditis (IE) is an infection involving the endocardial surface of the heart, including the valvular structures, the chordae tendineae, sites of septal defects, or the mural endocardium.

Question 2

Endocarditis (infective): Aetiology

Answer 2

• Viridans group streptococci
• Staphylococcus aureus
• Enterococci
• Coagulase-negative staphylococci
• Haemophilus parainfluenzae
• Actinobacillus
• Streptococcus bovis
• Fungi
• Coxiella burnetii
• Brucella species

Question 3

Endocarditis (infective): Risk factors

Answer 3

• prior history of infectious endocarditis
• presence of artificial prosthetic heart valves
• certain types of congenital heart disease
• post-heart transplant (patients who develop a cardiac valvulopathy)
• IV drug use (introduces bacteria)

Question 4

Endocarditis (infective): Pathophysiology

Answer 4

• IE typically develops on the valvular surfaces of the heart, which have sustained endothelial damage secondary to turbulent blood flow.
• As a result, platelets and fibrin adhere to the underlying collagen surface and create a prothrombotic milieu.
• Bacteraemia leads to colonisation of the thrombus and perpetuates further fibrin deposition and platelet aggregation, which develops into a mature infected vegetation

Question 5

Endocarditis (infective): Cinical manifestations: key presentations, other symptoms and signs

Answer 5

• All patients with bacteraemia should be suspected of potentially having IE
  
  • particularly those with an audible murmur
• Acute: Patients often present with signs and symptoms of peripheral or central emboli, or with evidence of decompensated congestive heart failure
  
  • Therefore, any patients who present with fever in conjunction with headache, meningeal signs, stroke symptoms, chest pain, dyspnoea on exertion, orthopnoea, or paroxysmal nocturnal dyspnoea need to be evaluated urgently for IE

Question 6

Endocarditis (infective): Investigations (diagnosis): 1st line, gold standard & other

Answer 6

• FBC
• serum chemistry panel with glucose
• urinalysis
• blood cultures

Question 7

Endocarditis (infective): DDx

Answer 7

• Rheumatic fever
• Atrial myxoma

Question 8

Endocarditis (infective): Management

Answer 8

• Broad-spectrum antimicrobial therapy is required empirically. Recommended antibiotic regimens may differ between countries and local guidance should be consulted.
• but obtain culture before use of antimicrobals
• The management of IE is guided by identification of the causative organism and whether the infected valve is native or prosthetic