Endocarditis

Question 1

What is infective endocarditis?

Answer 1

Infective endocarditis is an endovascular infection of cardiovascular structures, including cardiac valves, atrial and ventricular endocardium, large intrathoracic vessels and intracardiac foreign bodies, e.g. prosthetic valves, pacemaker leads and surgical conduits

Question 2

What is the prognosis for infective endocarditis?

Answer 2

Without treatment the mortality approaches 100% and even with treatment there is a significant morbidity and mortality

Question 3

What is the pathophysiology of infective endocarditis?

Answer 3

Endocarditis is usually the consequence of two factors:
1. The presence of organisms in the bloodstream (poor dental hygiene, IV drugs, infection)

2. Abnormal cardiac endothelium facilitating their adherence and growth (Damaged endocardium promotes platelet and fibrin deposition which allows organisms to adhere and grow)

Question 4

What determines the clinical presentation of infective carditis?

Answer 4

The clinical presentation of infective endocarditis is dependent on the organism and the presence of predisposing cardiac conditions

Question 5

What are clinical features of infective endocarditis?

Answer 5

Malaise, Clubbing, Pyrexia

Murmurs, Cardiac failure, haematuria

Petechiae, Osler’s nodes, Janeway lesions, splinter haemorrhages

Splenomegaly, joint stiffness

Question 6

What clinical events give rise to the suspicion of infective endocarditis?

Answer 6

New valve lesion or murmur
Embolic event with unknown origin
Sepsis of unknown origin

Question 7

What system is used to diagnose infective endocarditis?

Answer 7

Duke criteria

Question 8

How would you use Duke’s criteria to diagnose infective carditis?

Answer 8

1. A microorganism is demonstrated by culture of a specimen from a vegetation, an embolism or an intracardiac abscess
2. Active endocarditis is confirmed by histological examination of the vegetation or intracardiac abscess
3. Two major clinical criteria, one major and three minor criteria, or five minor criteria are met.

Question 9

What are major criteria for in Duke’s criteria for infective carditis?

Answer 9

1. A positive blood culture for infective endocarditis
2. A persistently positive blood cultures
3. A positive serological test for Q fever
4. Echocardiographic evidence of endocardial involvement:
5. New valvular regurgitation

Question 10

What are minor criteria for in Duke’s criteria for infective carditis?

Answer 10

1. Predisposition: predisposing heart condition or intravenous drug use
2. Fever: temperature ≥38°C
3. Vascular phenomena
4. Immunologic phenomena
5. Microbiological evidence
6. Echocardiogram

Question 11

What investigations would you do to diagnose infective carditis?

Answer 11

Echocardiography is an extremely useful tool if used appropriately

Question 12

How would you manage infective endocarditis?

Answer 12

4-6 weeks course of antibiotics

Usally double dual therapy for synergistic effect (IV)

Often penicillin/gentamicin/vancomycin

Question 13

How do you know if a patient with infective endocarditis is responding to medication?

Answer 13

Most patients with infective endocarditis should respond within 48 hours of initiation of appropriate antibiotic therapy. This is evidenced by:

1. Resolution of fever
2. Reduction in serum markers of infection
3. Relief of systemic symptoms of infection