aortic stenosis and regurg Flashcards
2 possible pathologies leading to A stenosis
- bicuspid valve
- degenerative
- calcification or rheum
what is the mech of problems with stenosis
- outflow obstruction
- pressure hypertrophy, diastolic dysfunction, ischemia
- Sx
- death
what is pressure hypertrophy
LV pressure overload induces genes that promote concentric hypetrophy - big wall
- end up with muscle bound heart that can’t pump forward properly
what are important points of progresson in A stenosis
- 50% reducdtion in orifice leads to minimal gradient
- beyond this there are exponential increases
- variable between people
3 clinical manifestation
- angina pectoris
- syncope
- dyspnea
2 parts of angina pectoris
- low supply
- endocardial compression
- assoc. CAD - high demand
- LV hypertrophy
- myocardial o2
- wall stress
what is syncope
- classically exertional
- may also be from an arrythmia
what is dyspnea
- LV hypertrophy
- diastolic dysfunction - progressive LV dilatiation and contractile failure
- systolic dysfunction
signs and Sx of HF
when is sudden death
- 3% per year in asymptomatic PT
- malignant tachy or brady cardia
what is nat. Hx
long asymptomatic latent period
- onset of Sx is a bad sign
what is murmur like in stenosis worsening
as it get worse, it comes later and get harsher
what is bicuspid valve
- prone to stenosis and regurg
- assoc. with AAA
- risk for aortic dissection, not coarctation
- risk for endocarditis
5 parts of workup
- ECG
- LA enlargement, LV hyper - CXR
- post stenosic Aortic dilatation - ECHO
- thick and restricted leaflets
- gradient and vavle area can be calculated - Cath
- gradient across valve and valve area - stresst testing
- for prognosis
3 severity levels and measurments
mild - 40mmHg
what is med. mgmt
mech problem = mech Tx
- afterload reducing drugs contraindicated
4 reasons stenosis important
- common
- major clinical implications
- morbid once Sx
- treatable
5 common errors in stenosis
- failure to disting sclerosis from stenosis
- failure to diagnoe/investigate
- failure to act once Sx there
- prescribing afterload reducing agents
- abrupt reduction in preload/afterload
3 possible causes of A regurg
- diseased valve cusps
- calc, bi cusp, rhuem - diseased aortic root
- acute patho
- dissection, trauma, endocarditits
what is pathophys is acute
- acute Vol overload leads to high filling P
- LV doesn’t have time to accom.
- stroke vol goes up a bit, but not enough to deal with all the extra
- low forward output and high L atrium pressure
what is patho in chronic
- get eccentric hypertrophy - cor bovinum
- v. large strok vol get blood forward well
- ejection fraction remains the same
- can stay compensated for a long time
what happens in decomp.
- eventual LV fibrosis and systolic dysfunction
- wall tension and pressure rises over time
- evenutally ejection fraction falls
what is natural Hx
- asymptomic for decades
- remodelling is asymptomaic for a while
- then get Sx and it is bad
3 main Sx of regurg
- palplitations - due to hyperdynamic stroke volume
- failure
- dyspnea on exertion, orthopnea, fatugue - angina, syncope
what is heart sound with regurg
high pitched early diastolic murmur
4 tests
- ECG - LVH
- CXR - megaly
- ECHO
- cath
5 parts of med mgmt
- surveillance ECHO
- avoid bradycardia
- vigilance against endocard
- diuretics
- vasodilators
indications for surg
definite - Sx with normal ejection fraction - Sx with mild decrease EF v. prob - Asx but with sever LV dilatation probable - severe LV systolic dysfunction
2 common errors
- failure to monitor for asymptomatic but irreversible LV remodelling
- over-reliance on meds on remodellig occurs
what is surg
valve replacment
