Aortic Valve Disease Flashcards
What are the 3 main causes/etiologies of aortic stenosis?
Congenital valve malformation i.e. Bicuspid aortic valve
Rheumatic
“Senile” calcific disease
What happens to the valve to cause stenosis in bicuspid aortic valve?
Wear and tear on the valve causes calcium to build up and inhibit opening
What happens to the valve to cause stenosis in rheumatic disease?
Fuses the comissures - causing scarring
What happens to the valve to cause stenosis in “senile” calcific disease?
Valve was normal but wear and tear caused build up of calcium
What factors does aortic stenosis have in common with coronary atherosclerosis?
Both more common in men, elderly, and patient with hypercholesterolemia
Derived in part from inflammatory process
Which etiology does aortic stenosis before the age of 60 indicate?
Bicuspid valve
Which etiology does aortic stenosis after the age of 60 indicate?
Probably “senile” calcific valve
What happens to the LV when there is aortic stenosis?
Aortic stenosis –> increased pressure in LV –> LV concentric hypertrophy –> increased LV stiffness
What symptoms make up the clinical triad of aortic stenosis?
Congestive heart failure
Angina Pectoris
Syncope (effort related)
What are physical diagnosis signs of aortic stenosis?
Murmur
Ejection click
Carotid artery pulsation
S4 sound (atrial gallop)
Describe the murmur heard in aortic stenosis
Crescendo-decrescendo between S1 and S2
Describe the ejection click heard in aortic stenosis
High frequency sound hear just after S1
Occurs at the time of aortic valve opening
Describe the carotid artery pulsation felt in aortic stenosis
Because of obstruction, upstroke of carotid may be slowed and can feel a slow rise in carotid on palpation
If stroke volume is low (later in disease), can palpate flow turbulence, felt as a vibration
Pulsus parvus et tardus (small and late pulse)
Describe the S4 sound heard in aortic stenosis
Tap right before S1 (presystolic)
Reflects a stiff left ventricle that you can feel at apex
What etiology of aortic stenosis does the ejection click suggest?
Bicuspid valve
What is a good sentence to remember that S4 goes with aortic stenosis?
“A stiff wall”
Where S4 is the “A”
What can you have the patient do to be able to hear the S4 better?
Have patient do sit ups (exercise) or have them squeeze your finger
This will acutely increase BP
What are clues of aortic stenosis that can be seen on echo?
Anatomy, detect calcification, evaluate opening of valve
Quantitate pressure gradient across the AV and calculate aortic valve area
Which patients should be given antibiotic prophylaxis before dental work?
Patients with:
Prosthetic valves
Previous endocarditis
Specific congenital heart disease
What are the two types of replacement valves?
Mechanical
Tissue
What type of valve should younger patients receive?
Mechanical
What type of valve should older patients receive?
Tissue
What are the advantages and disadvantages of mechanical valves?
Advantage - long lasting
Disadvantage - need anticoagulation
What are the advantages and disadvantages of tissue valves?
Advantage - do not need anticoagulation
Disadvantage - degenerates over time
What are possible complications of prosthetic heart valves?
Thromboembolism Bleeding (secondary to anticoagulation) Valve dysfunction Valve regurgitation Endocarditis
What other aortic issue is bicuspid aortic valve associated with?
Aortic dilations, aneurysms and dissections
Due to accelerated degeneration process that results in structural weakness of wall
What are the two major etiologies that lead to aortic regurgitation?
Abnormalities of valve leaflet
Dilatation of aortic root
What happens to the LV when there is chronicaortic regurgitation?
Aortic valve leaflets cannot coapt –> backward runoff –> volume overload of the LV –> LV dilatation –> increased LV diastolic volume –> wall stress –> formation of new sarcomeres “eccentric hypertrophy”
What occurs to the systemic diastolic pressure and systemic systolic pressure in chronic aortic regurgitation?
Decreased systemic diastolic pressure - aortic valve cannot maintain pressure in aorta in diastole
Increased systemic systolic pressure - large volume of blood goes backwards, increasing the SV from LV into aorta
Causes WIDE PULSE PRESSURE
What is concentric hypertrophy and is it seen in aortic stenosis or aortic regurgitation?
Pressure overload leads to fattening of myocytes and sarcomeres added in parallel, causing LV hypertrophy
Aortic stenosis
What is eccentric hypertrophy and is it seen in aortic stenosis or aortic regurgitation?
Volume overload leads to stretching of the myocytes and sarcomeres added in series, causing LV dilation
Aortic regurgitation
What are symptoms of aortic regurgitation?
Congestive heart failure
Occasionally angina
Wide pulse pressure
What are physical signs of aortic regurgitation?
Wide pulse pressure (i.e. 200/40)
Cardiomegaly (LV dilated)
Murmur
Describe the murmur heard in aortic regurgitation?
Early diastolic high-pitched blowing murmur (heard after S2)
In what location and what position (of the patient) is the aortic regurgitation murmur best heard?
Location = sternal border Position = leaning forward
What are some of the peripheral findings caused by the wide pulse pressure in aortic regurgitation?
Synchronous head bob (de Musset’s sign)
Uvula pulsing
Capillaries of finger
Carotid double beating
What are clues of aortic regurgitation that can be seen on echo?
Aortic regurgitation flow
Determine LV function
What are the causes of acute aortic regurgitation?
Secondary to trauma, endocarditis, aortic dissection
Severe = surgical emergency
Why is acute aortic regurgitation so dangerous?
LV does not have time to dilate and acute increase in LV pressure can be abruptly reflected back to the lungs, causing acute pulmonary edema and death
How do the physical findings of acute aortic regurgitation differ from those of chronic aortic regurgitation?
Signs of chronic AR are often absent in acute AR
- NO cardiomegaly (LV hasn’t had time to dilate)
- NO wide pulse pressure
- NO long diastolic blowing murmur
Why is there no widened pulse pressure in acute aortic regurgitation?
Regurgitant volume into a non-dilated LV will cause LV diastolic pressure to rise
Diastolic pressure in aorta can only drop as low as diastolic pressure in LV - so diastolic pressure in aorta will not be low
LV cannot respond with increased stroke volume - so systolic pressure in aorta may not be elevated
Thus, wide pulse pressure is gone
Why is there no murmur in acute aortic regurgitation?
Early equilibration of aortic and LV diastolic pressures shortens the murmur
