Valve Disease Flashcards
what is the structure of the aortic valve?
3 leaflets - left, right and posterior
when does the aortic valve open?
systole
when does the aortic valve close?
diastole
what happens to a valve in stenosis?
doesn’t open all the way
what happens to a valve in regurgitation?
doesn’t close all the way
how far does the aortic valve open in stenosis compared to normal
<1cm vs 3-4cm
what is the pathophysiology of aortic stenosis?
Mechanical stress or repeated inflammation over time which damages endothelial cells around the valves causing fibrosis an calcification
Valves become stiff and can’t open as easy
what is the impact on the heart in aortic stenosis?
left ventricle has to generate higher pressure to get same amount of blood through valve, undergoes hypertrophy
what causes the murmur in aortic stenosis?
• Since the blood has to flow though a narrow opening theres turbulence which creates a noise or a murmur which initially gets louder as more blood passes through the opening and then quitter as the amount of blood flowing subsides because less remains in the ventricle
what are the causes of aortic stenosis?
Congenital - bicuspid valve, Williams syndrome
Senile Calcification
Age
Chronic Rheumatic Fever
what murmur is heard in aortic stenosis?
Ejection Systolic murmur
crescendo-descendo murmur
what other clinical features are present in aortic stenosis?
Syncope, dyspnoea, fatigue Slow rising pulse with narrow pulse pressure difference Heave - apex beat not displaced Signs of HF AF Angina
what three investigations can be done for aortic stenosis?
ECG, doppler echo, cardiac catheterisation
what features are present in the ECG of someone with aortic stenosis?
o L – LBBB – due do calcification
o L – Left Axis Deviation
o L – LVH
o P – Poor R wave progression (i.e. depolarisation of the ventricles is slow)
what are the pressures of the different types of aortic stenosis?
o 0 mmHg – normal valve
o <30 mmHg – mild aortic stenosis
o 30-50 mmHg – moderate aortic stenosis
o >50 mmHg – severe aortic stenosis
what is the management of aortic stenosis?
valve replacement (prosthetic or metal)
What are the complications associated with aortic stenosis?
HF, Microangiopathic haemolytic anaemia
What are the acute causes of aortic regurgitation?
infective endocarditis, ascending aortic dissection, chest trauma
what are the chronic causes of aortic regurgitation?
congenital, connective tissue dsorders (marfaans, ehlers-danlos), rheumatic fever, Takayasu arteritis, rheumatoid arthritis, SLe, pseudoxanthoma elasticum, appetite suppressants, seronegative arthroceles (ankylosing spondylitis, reiters syndrome, psoriatic arthropathic), hypertension, osteogenesis imperfecta, syphilitic aortitis
what is a common cause of aortic regurgitation?
aortic root dilation
what is the mechanism of aortic regurgitation?
valve does not close properly causing blood to flow back from the aorta into the left ventricle during diastole or ventricular filling
what causes the murmur heard in aortic regurgitation
early decrescendo murmur caused by the flood flowing back through the valve
what are the two consequences of aortic regurgitation?
Hyperdynamic circulation
Eccentric Ventricular Hypertrophy
How does aortic regurgitation cause hyperdynamic circulation?
- Systole more blood pumped out of the heart requires more pressure, so systolic blood pressure increases
- Diastole if theres less blood volume in the aorta as some leaks back down, which means diastolic BP decreased
- A higher systolic BP and lower diastolic BP means an increase in pulse pressure
