Infective Endocarditis

Question 1

Definition of infective endocarditis

Answer 1

Infection of the endocardium by microbes that leads to large & friable vegetations defects at the line of closure/edge of defect

Question 2

Original of infection (greys anatomy)

Answer 2

Abscess
Poor dental hygiene
Systemic sepsis
IV drug use (right side of heart)
Catheter
Post operation/haemodialysis

Question 3

What is the 2 categories of risk factors for infective endocarditis

Answer 3

1. Host
2. Intracardial

Question 4

What is the 4 feature of acute bacterial infective endocarditis

Answer 4

Highly virulent microbe
Destruction of normal tissue = highly destructive & morbidity
Vegetations & abscess (valve destruction arrhythmia, heart & major arteries)
Papillary muscle & chordae tendinae rupture

Question 5

What is the diagnostic criteria for infective endocarditis & requirements

Answer 5

Duke criteria
1. Clinical: 2 major, 1 major & 3 minor, 5 minor
2. Pathological: diagnosis if present

Question 6

Complications of infective endocarditis (ARISE)

Answer 6

Abscess erode ring = myocardium
Rupture of valve/cords
Immune complex formation at kidney = glomerulonephritis
Septacemia
Emboli (septic)

Question 7

Pathogenesis of infective endocarditis

Answer 7

1. Valve damage causing platelet & fibrin depositions forming a NBTE where bacteria attaches, colonies & forming a mature vegetable
2. Infection in other membranes & trauma leading to bacteraemia, adherence of bacteria, colonies & forming mature vegetation

Question 8

Who receives prophylaxis for infective endocarditis

Answer 8

Cardiac transplant, prosthetic valve or previous infective endocarditis before procedure

Question 9

Treatment for infective endocarditis

Answer 9

Empiric antibiotics until lab results then directed antibiotics for 4-6 weeks IV

Question 10

What is the 4 component of the endocardium

Answer 10

True endocardium
Valves
Chordae tendinae
Papillary muscles

Question 11

What is the 3 microbes that can cause infective endocarditis

Answer 11

1. Bacteria w/ high or low virulence (a haemolytic streptococci, + in chains)
2. Fungi that has larger vegetations in IV drug users/immunocompromised individuals
3. Viral

Question 12

What is characteristic of the vegetations in infective endocarditis

Answer 12

At mitral or aortic valve
Forms lines of Zahn (fibrin, platelets & organism)
Friable (breaks off & proliferate)

Question 13

What is the 6 host risk factors of infective endocarditis

Answer 13

Immunocompromised
Neutropenia
Malignancy
Poor dental hygiene
IV drug user
Male over 60 years

Question 14

What is the 7 intracardial risk factors of infective endocarditis

Answer 14

Foreign bodies: catheter, prosthetic valve
Heart abnormalities: RHD, mitral valve prolapse, degenerative calcified stenosis, congenital abnormalities, bicuspid aortic valve

Question 15

What is the 4 ways on which infective endocarditis can be classified

Answer 15

1. Left & right
2. Infective vs non-infective
3. Native vs prosthetic valve
4. Acute vs subacute

Question 16

What is 7 clinical feature of acute bacterial infective endocarditis

Answer 16

Rapid onset, fever, rigours, malaise, sudden death, chest pain & SOB

Question 17

What is the 4 feature of subacute bacterial infective endocarditis

Answer 17

Low virulence
Damaged already damage tissue
Prolonged & low morbidity
Smaller vegetations

Question 18

What is 4 clinical feature of subacute bacterial infective endocarditis

Answer 18

Slow onset, fatigue, loss of weight & appetite

Question 19

What is 5 clinical feature of infective endocarditis

Answer 19

Murmur
Clubbing
Splinter haemorrhage
Janeway lesions
Septic emboli causing a CVA

Question 20

What is the 2 special investigations with infective endocarditis

Answer 20

1. Echocardiogram
2. Blood culture

Question 21

What is the 3 criteria’s for taking blood culture in infective endocarditis

Answer 21

1. Aseptically
2. 2 separate cultures
3. Before antibiotics

Question 22

What is the 2 echocardiograms with infective endocarditis

Answer 22

1. Transoesophageal
2. Transthoracic