Endocarditis

Question 1

What causes bicuspid aortic valves (should be tricuspid)?

Answer 1

=Congenital

Abnormal aortic cusp formation during valvogenesis

Conjoined cusp

Question 2

Why are patients with a bicuspid valve at a higher risk of developing endocarditis?

Answer 2

Abnormal blood flow over valve

Abnormal valve tissue

Patient= at greater risk of microbes in blood sticking to valve cusp

Question 3

What are the 2 main risk factors for endocarditis?

Answer 3

1. Structural defects (endocardium= non sticky and normally resistant to bacterial seeding)
2. Injectable drug use

Question 4

What is the mechanism for infection of endocarditis?

Answer 4

Vegetation formation

–> binds to valves/mural endocardium

Aberrant blood flow- cllection of fibrin. platelets and scant inflammatory cells

eg Staph aureus has fibronectin binding proteins–> binds to intact endothelium

Question 5

Why can endocarditis be difficult to treat?

Answer 5

Micro colonies of bacteria remain dormant

Colonies tend to embolise- causing sepsis and reinfection og vegetation

Question 6

What are the 3 hallmarks of infection?

Answer 6

1. Constitutional symptoms= cytokine mediated
2. Local spread of infection- destruction of myocardium
3. Distal blood borneseptic embolisation

Question 7

What are the clinical features of endocarditis?

Answer 7

• Fever
• Heart murmur
• Other cardiac complications
• Embolic features
  
  • eg Janeway lesions (haemorrhagic nodular lesions with irregular border- micro-absess formation and loaclised necrosis

Question 8

What are splinter haemorrhages?

Answer 8

Question 9

What are Roth spots in the eye

Answer 9

Question 10

What are Oslers nodes?

Answer 10

Painful, erythmatous nodules on pads of fingers and toes