Infective endocarditis Flashcards
why do we need to know about IE?
what happens if w have valve disease?
- stenosis = maybe stiff and not open well
- may not prevent regurgitation (back flow) (incompetent valves)
describe the lungs in fetus ?
- not inflated because we dont use them as much as we get oxygen from placenta from mothers circulation
- blood coming back to heart is therefore oxygenated
- another reason why lungs aren’t inflate dis because if they were perfused they would generate a lot if resistance = we don’t need this as it would cause problems with heart
- we dont need lungs to oxygenate blood so we need to bypass lungs = 2 ways
what are the 2 ways in which we bypass lungs in foetus ?
- communication by foramen ovale between RA and LA then carries onto LV Any blood that is pumped into PA comes across short circuit called ductus arteriosus = communicates PA and aorta (remember the blood pumped thru heart is oxygenated by mother so no need to go to lungs to get oxygenated)
- thru the Foramen ovale some blood which is pumped from the RA doesn’t go into the RV and goes into LA then LV and then into aorta
what is CHD split into ?
- failure of heart to complete changes at birth
- failure of heart to develop normally
what happens which leads to failure of complete change at birth?
failure of ductus arteriosus and foramne ovale closure which can lead to patent DA and FO
- theyre going to interrupt profusion of lungs
- as we get older pressures with heart and around heart become a bit more = heart has to deal with high BP and amounts if blood
what can lead to failure of heart to develop normally?
- transposition of great vein = VC and PV are swapped so VC goes in LA and PV into RA
- dextrocardia = heart is positioned on RHS rather than LHS
- atrial septal defect
- ventricular dental defect
- narrowing of valve = increase pressure and increases resistance to blood flow
what is the most major heart defect ?
tetralogy of fallot
- common in kids
- 4 abnormalities :
1. ventricular septal defect = hole between RV and LV = means right side does loads of work leading to
2. right ventricular hypertrophy
3. pulmonary stenosis= pulmonary artery and valve can be stenosed = increases resistance of blood flow adds to work load of RV
4. overriding aorta = you have ventricular septal defect and instead of the aortic valve being in edge of left ventricle, its in the middle = both the LV and RV pump blood thru aortic valve
can lead to :
heart failure
poor blood oxygenation
poor lung perfusion
- dont need to know in too much detail
what can a stenosed valve lead to ?
- slow blood flow
- virchads triad = thrombosis
what can a incompetent valve lead to?
- back flow
- Eddys
- failure of blood circ = heart failure
- lead to thrombosis
what happens if we have stenosis in heart valve ?
- increased load on heart as tries to push blood
- on the other Side of heart we get eddies and turbulent blood flow
- iff valves very narrow = blood passing thru= fast blood = jet damage to endothelium of heart = damage endolitheial (bleeding lec) can cause blood clots = thrombus within heart
what happens if we have regurgitation of heart valves ?
- well get heart failure
- prothrombtic problems
epidemiology of rheumatic valve disease
rheumatic
epidemiology of calcification/ degeneration of valves
epidemiology of CHD
what are the effects of valvular/ CHD?
- relevant to how we treat pts
name one of the treatments for valve disease ?
prosthetic heart valves
what is a transcatheter aortic valve implant (TAVI)?
- new way of treating faulty valves but will still get problems in terms of anticoagulants so bear in mind in clinics
what are the risks associated with pts who have TAVI or mitral valve replacement ?
embolism = eg. risk of stroke
what is infective endo?
infection of endocardium including heart valves
- not that common 2-5/ 100k pop
more common in;
- ppl with valve abnormalities/ prosthetic valves
- but 50% of cases have normal hearts
- Intra venous drug abusers = rmalnurousied or immunocompromised
- immune compromised pt eg. who take potent anti inflammatorys or immune modulating drugs are at risk of any infection
what is I.E caused by?
- bacteraemia = bugs in valve an settle in valves or heart abnormalities
- if you are immune suppressed more likely to have bacteria in blood
- bacterial also fungal infection of clots on valve leaflets
- vegetations (fibrin, WBC, bacteria) collect on surface of valve leaflets
what er the clinal features of IE?
what are the systemic problems that can occur with IE?
vasculitis can produce inflammation around body which can lead to hemorrhagic spots in skin
what are the main issues with IE?
- vegetations can give rise to emboli which can cause eg. stroke ….
what is the prognosis of IE?
6-30% mortality
one episode predisposes to further episodes
what are the risk factors of IE?
- susceptible heart= heart with valvular heart disease, artificial heart valve, previous IE, CHD, hypertrophic cardiomyopathy
- bacteraemia= caused by instrumentation of areas with high bacterial loads eg. dent procedures , upper lower GI, skin mouth, urogenital.
what the 2 types of CHD in which paediatricians can categorise ?
cyanotic CHD = blue discolouration in limbs and lips due to tetralogy of fallot (can’t perfuse lungs properly) , transposition of great arteries, tricuspid atresia (tricuspid doesn’t form)
acyanotic CHD = lungs are working well = less dangerous
both are risk factors for IE
what do we say to the pt if they have a heart murmur and cardiac condition from the special consideration sub group ?
- offer advice on prevention as out lined for routine management
- ## contact pts. cardiologist to determine if prophylaxis should be considered for invasive procedures
which patients are in special considerations group ?
with murmur and :
previous IE
prosthetic valve
not pacemakers
pts with CHD
what is routine management ?
for both special category pts and just heart murmur pts
- we discuss risk and benefits: anaphylaxis, resistance, c. diff
what is the non routine management for special category ppl?
what are invasive dental procedures in terms of pts with IE?
what are non invasive dental procedures in terms of IE pts?
what advice do we give pts with infective endo?
- even if we give them prescription antibiotics thye need to knw risks as thye may still get IE
- need to contact A and E
