Endocarditis

Question 1

What is infective endocarditis? What part of the heart is usually damaged with this infection?

Answer 1

infection of the endocardial surfaces of the heart (usually VALVULAR damage), usually bacterial cause

Question 2

What are the two main types of endocarditis?

Answer 2

Acute (emergency) and Subacute (person not that sick)

Question 3

What type of heart valves does subacute E usually affect? what side of the heart does it usually affect? What type of organisms is it caused by

Answer 3

previously damaged heart valves
left sided- high pressure side (mitral usually affected more than aortic valve)
less virulent organisms

Question 4

What type of heart valves does acute E usually affect? what side of the heart does it usually affect? What type of organisms is it caused by? what two activities is it typically related to?

Answer 4

previously healthy valves
right sided (tricuspid more for intravenous drug use-IVDU)
virulent organisms
rapidly progressive
IVDU and heart caths

Question 5

what type of aortic valve is at risk for endocarditis?

Answer 5

bicuspid aortic valve (congenital defect)

Question 6

are endocarditis infecting organisms the same for all types of endocarditis?

Answer 6

NO
different organisms in acute vs subacute
different organisms in prosthetic (tissue/mechanical) vs natural valve
IVDU- different organisms

Question 7

six underlying causes of SBE (subacute bacterial endocarditis)

Answer 7

hx of rheumatic fever with valve vegetations
MVP
calcified Aortic stenosis in elderly
congenital bicuspid AV
artificial valves
injury from cath

Question 8

What is a good culture medium for endocarditis infectious organisms?

Answer 8

heart valve vegetation

Question 9

How can dental work cause endocarditis?

Answer 9

During dental work, mouth bacteria can easily get in the blood (bacteremia); bacteria introduces vegetation to the valves or will travel to foreign tissue (artificial valve)

Question 10

What is the most common bacteria that causes SBE?

Answer 10

S. viridans (viridans streptococci) from mouth (dental work)

Question 11

How do SBE infectious organisms damage valves?

Answer 11

Bacteria travels to the valves and create a mass called vegetation. this accelerates platelet aggregation and fibrin deposition
As bacteria multiply, there is continued layering of platelets and thrombin (thickness prevents neutrophils from killing bacteria)

Question 12

What are three complications of SBE?

Answer 12

embolization (vegetation travels and can lead to distant abscess formation or Cerebral vascular accident)
slowly progressive valve damage
possible conduction defects

Question 13

SBE symptoms

Answer 13

night sweats, fever, weight loss, malaise

Question 14

A person with SBE might have a history of….

Answer 14

valvular disease, IVDU, dental work, long hx of heart murmur (chronically sick pt)

Question 15

What is the ABX therapy for SBE?

Answer 15

empirical for 4-6 weeks to cover organisms by hx

Question 16

Why is ABE worse than SBE

Answer 16

SBE is a chronic infection that is not immediately threatening to valvular integrity
ABE can quickly destroy valves and lead to serious complications (heart failure)

Question 17

ABE symptoms

Answer 17

dyspnea/cough/CP
confusion/mental status
higher fevers than SBE
CHF
marked leukocytosis (compared to SBE)
septic meningitis/arthritis

Question 18

four manifestations of ABE

Answer 18

Janeway lesion- non-tender, small erythematous or haemorrhagic lesions on the palms or soles
conjunctival petechiae
Pustulonecrotic embolic lesions in toes
splinter hemorrhages in nails

Question 19

What is tx for ABE?

Answer 19

immediate empiric ABX and start blood cultures (for more definitive ABX)
Tx should last 4-6 weeks
maybe septic embolization if fever doesn’t resolve with ABX; might need valve replacement

Question 20

how does ABX prophylaxis prevent endocarditis?

Answer 20

it prevents colonization of vegetation on the valves when bacteria is in the blood (ex: dental work)

Question 21

What is the dental ABX prophylaxis dosage/frequency?

Answer 21

2 grams of amox 1 hr before procedure

Question 22

what two other surgical procedures might need ABX prophylaxis to prevent endocarditis?

Answer 22

GI and GU procedures

Question 23

What pts are considered highest risk and MUST get prophylaxis ABX?

Answer 23

prosthetic valve pts
pts with previous or reoccurring IE
valvopathy following heart transplant
Congenital heart defect: repair with prosthetic tissue, repaired but some defect is still present, unrepaired defect

Question 24

Patients with these two type of cardiac conditions might also receive ABX prophylaxis (even though guidelines dont say so)

Answer 24

pts with MVP or a murmur (aortic or mitral)