Infective Endocarditis

Question 1

What is the endocardium and what does it include?

Answer 1

Inner lining of the heart and includes the heart valves

Question 2

Is infective endocarditis fatal?

Answer 2

Often fatal
6 month mortality rate is 20-25%

Question 3

What is endocardial damage caused by?

Answer 3

Turbulent blood flow from valve problems
Congenital heart disease
Cardiomyopathy
Cardiothoracic surgery / implanted foreign materials (pacemakers)

Question 4

What does endocardial damage expose?

Answer 4

Sub-endocardial matrix, where platelets and fibrin attach –> thrombus

Question 5

How can bacteria enter the circulation?

Answer 5

Poor dental hygiene
Sepsis
IV drug user

Question 6

What happens when bacteria enters the circulation?

Answer 6

Avoids destruction by the immune system and sticks to the damaged endocardial surface thrombus

Question 7

Why are left side valved affected more than the right?

Answer 7

Higher pressure –> more turbulent blood flow

Question 8

Symptoms of subacute infective endocarditis

Answer 8

Fever
Tiredness
Night sweats
Weight loss

Question 9

Symptoms of acute infective endocarditis

Answer 9

Severe febrile illness
Heart murmurs
Embolism
Cardiac failure
Renal failure

Question 10

Vascular phenomena in infective endocarditis

Answer 10

Bacteria travels through circulation = septic emboli
Deposits in the skin and mucous membranes = small haemorrhages
In hands and feet = Janeway’s lesions
In nails = splinter haemorrhages
Larger septic emboli –> blocks blood vessels –> ischaemic strokes, limb ischaemia, pulmonary embolism

Question 11

Immunological phenomena in infective endocarditis

Answer 11

Immunoglobulins made by immune system bind to bacterial proteins to remove but instead they clump together = immune complex
Lots of immune complexes –> inflammation
In hands = Osler’s nodes (tender)
Renal damage