Infective endocarditis (IE)

Question 1

What two symptoms suggest endocarditis until proven otherwise?

Answer 1

• Fever

* New murmur

Question 2

A fever lasting how long in a patient known to be at risk of IE must prompt blood cultures?

Answer 2

• 1 week

Question 3

What is the percentage of IE occurring on normal valves?

Answer 3

• 50%

Question 4

How does IE occurring on normal valves present?

Answer 4

• Acute course

* Presents with acute heart failure +/- emboli

Question 5

What is the commonest cause of IE involving normal valves?

Answer 5

• S. Aureus

Question 6

What are the risk factors of IE involving normal valves? (6)

Answer 6

• Dermatitis
• IV via the skin
• Renal failure
• Organ transplantation
• DM
• Post-op wounds

Question 7

What is the course of IE on abnormal valves?

Answer 7

• Subacute

Question 8

What is the risk factors for IE on abnormal valves? (6)

Answer 8

• Aortic or mitral valve disease
• Tricuspid valves in IV drug users
• Coarctation (of the aorta) – congenital condition where the aorta is narrow
• Patent ductus arteriosus – (blood vessel connecting the pulmonary artery and the proximal descending aorta stays patent)
• VSD (ventricular septal defect)
• Prosthetic valves

Question 9

What is the most common cause of bacteraemia? What are the other infectious agents? (5) What group is rarely the cause?

Answer 9

• Strep viridians
• Staph aureus/epidermis / diphtheroids / microaerophilic / streps.
• Rarely HACEK – gram -ve bacteria

Question 10

What are the septic signs of IE? (8)

Answer 10

• Fevers / rigors / night sweats / malaise / weight loss / anaemia / splenomegaly / clubbing

Question 11

What are the cardiac lesion signs of IE? (2)

Answer 11

•Any new murmur / changing pre-existing murmur

Question 12

What may vegetations in IE lead to? (3)

Answer 12

• Valve destruction / severe regurgitation / valve obstruction

Question 13

What may an aortic root abscess lead to?

Answer 13

• Prolongation of the PR interval –> complete AV block

* LVF is a common cause of death

Question 14

What are the signs of immune complex deposition in IE? (7)

Answer 14

• Vasculitis / microscopic haematuria / glomerulonephritis / acute renal failure / roth spots / splinter haemorrhages / osler’s nodes

Question 15

Where may embolic phenomena occur in IE?

Answer 15

• Left-sided IE – abscesses in the brain / heart / kidney / spleen / skin (Janeway lesions)
• Right-sided IE – lung

Question 16

What is pathognomonic of IE?

Answer 16

• Janeway lesions together with Osler’s nodes