Valvular heart disease - aortic Flashcards
What is the normal size of a aortic valve
3-4cm
What size is a aortic stenosis
<1.5cm -2cm
What is the aetiology of aortic stenosis
Degenerative - calcification = senile aortic stenosis
Rheumatic
Bicuspid stenosis
What is the pathophysiology of rheumatic disease that results in aortic stenosis
Adhesion, fusion of the commissures and retraction and stiffening of the free cusp margins
What is the pathophysiology of degenerative that results in aortic stenosis
a slow inflammatory process resulting in thickening and calcification of the cusps from base to free margins
What is degenerative aortic stenosis linked to
athlersclerosis
Why is the aortic valve the most likely to be affected degeneratively
As is the valve with the highest pressure of blood passing through it
How does aortic stenosis result in myocardial ischaemia
Increased LV systolic pressure
leads to left ventricular hypertrophy
Increase left ventricular end-distolic pressure
left atrial pressure increases causing pulmonary hypertension
myocardial oxygen consumption increase due to myocyte size increasing
leading to higher susceptibility to Myocardial ischaemia
to cause Left Ventricular failure
Whats is the cardinal symptoms of aortic stenosis
Chest pain (angina)
Syncope/Dizziness (exertional pre-syncope)
Breathlessness on exertion
Heart failure
What does it means when symptoms become apparent in aortic stenosis
Need immediate treatment within a month as follows a long asymptomatic phase
What is the clinical signs on examination of aortic stenosis
Pulse – small volume and slowly rising JVP – prominent if RH failure present, low BP Vigurous and sustained apex beat RV heave Auscultation: Systolic murmur Normal first heart sound less audible second heart sound Harsh ejection sound
What is the investigations for aortic stenosis
ECG CXR Cardiac catheterisation Echocardiography Cardiac Magnetic Resonance
What is show in an ECG of aortic stenosis
will show LVH – taller R waves or ST segment abnormalities
What does a chest x ray show in aortic stenosis
Not conclusive unless aortic valve is calcified
What is the purpose of Cardiac catheterisation
measure peak pressure in ventricle (below) and in aorta (above)
What is the disadvantage to cardiac catheterisation
shows pressure at different moments in time so doesn’t really show stenosis severity.
very invasive and can lead to calcification breaking off and causing an emboli.
Echocardiography is a less invasive but why is it a far more useful method of investigation
Demonstrates: the cusp motility LV function Hypertrophy asses pressure gradient and aortic valve area
therefore gives a better indication to severity
Who is medical treatment limited to in those who develop atrial stenosis
Those who develop heart failure
What is the medical treatment for atrial stenosis
Surgery: repair or replacement
what is the two aetiologies of aortic regurgitation
Due to dysfunctional leaflets
Due to dilatation of aorta
What is the aetiology of dysfunctional leaflets to cause aortic regurgitation
Bicuspid aortic valve
Rheumatic heart disease
Endocarditis
Myxomatous degeneration
What is the aetiology of the dilation of the aorta to cause aortic regurgitation
Connective tissue disorders
due to a pathological process e.g. hypertension
What is the pathophysiology of aortic regurgitation that leads to left ventricular failure
The left ventricle commodities for both stroke volume and regurgitant volume
This increases left ventricular end-diastolic volume and left ventricular systolic pressure
Leading to LV hypertrophy
Greater size myocytes increase myocardial oxygen consumption
causing left ventricular failure
What is the symptoms for chronic aortic regurgitation
Long asymptomatic phase
Exertional breathlesness
what is the clinical signs of aortic regurgitation found in examination
Pulse – large volume and retracting/collapsing
(Corrigan sign)
Wide pulse pressure e.g. 170/40mmHg
Hyperdynamic, displaced apex beat
Auscultation:
DIASTOLIC MURMUR – very difficult to hear.
Comes between Second heart sound and first heart sound
Very faint and very early
Why is the apex beat hyperdyanmic and displaced in AR
due to volume overloaded heart
What position must the patient be sat in to hear the atrial regurgitation
patient must be sat up, leaning forward, and auscultate on held exertion
What is the investigations for aortic regurgitation
ECG CXR Cardiac catheterisation Echocardiography Cardiac Magnetic Resonance
Why is ST/T changes seen in an ECG on aortic regurgitation
due to Left Ventricular being strained
What does the chest X-ray show in aortic regurgitation
cardiomegaly - abnormal enlargement of the heart
What investigation is now obsolete in investigating aortic regurgitation
Cardiac catheterisation
What does an echocardiography show in aortic regurgitation
demonstrates the AV cusp anatomy:
(thickening, prolapsing, number of cusps, vegetations)
LV function, dilation, hypertrophy
shows the prolapsing/backflow of blood
What medical treatment is used to delay the timing for surgical intervention
Vasodilator therapy
How is aortic stenosis differentiated from aortic sclerosis
Loss of aortic secondary heart sound
On an ECG and ECHO what is the atrial ventricular pressure gradient that shows left ventricular hypertrophy
> 50mmHg
