Aortic Valve Stenosis-Merkin Flashcards
Types of location aortic stenosis
From least to most common: Supravalvular, Descrete subvalvular (DSS), Valvular
In congenital aortic stenosis, which congenital cuspid state is generally involved?
Most severe: unicuspid. Most common: bicuspid. Also: tricuspid or fused or quadricuspid.
What can be seen of the valve in a longitudinal echo?
Only 2 cusps.
What can be seen in a cross-sectional/short-axis echo?
All 3 cusps.
What is seen in aortic stenosis on an echo?
Less laminar flow leads to turbulence, calcification and fibrosis of valve leading to AS.
Types of acquired aortic stenosis
Rheumatic, degenerative/senile (most common, increased incidence with age), atherosclerotic (usually with familial dyslipidemia
Pathophysiology of aortic valve disease
- Gradual obstruction of LV outflow, 2. Increased intraventricular pressure, 3. Concentric LVH, 4. Maintained CO with increased EDP
In severe aortic stenosis, what usually brings on symptoms?
CO fails to rise normally during exercise. Later, CO declines at rest and CHF ensues.
Clinical manifestations of aortic stenosis
Long latent period, cardinal manifestations: angina pectoris (d/t decreased coronary flow, usually only on exercise), syncope (can’t increase circulation to brain effectively), heart failure (dyspnea d/t LVF)
What appears on a physical exam of aortic stenosis?
Pulsus tardus and parvus, systolic thrill, A2, ejection systolic mumur
Pulsus tardus et parvus
Upstroke of pulse is slow and weak/small.
What is systolic thrill?
Flow through valve turbulant, fingers over aortic oscultation point will be able to feel thrill (murmur).
Heart sounds in aortic stenosis
S2 will be increased in a young person whose valve is still pliable, in elderly person will be calcified and more muffled. Sometimes hear S4 sound.
Aortic stenosis murmur
Middle of systole, diamond shaped (louder then softer)
What lab tests should be performed in aortic stenosis?
ECG (LVH, conduction abnormalities), CXR, angiography, Echo
What test is done to follow up on aortic stenosis patients?
Echo, angiography is too invasive and expensive.
What is the definition of a mild aortic stenosis?
Jet velocity 1.5cm^2
What is the definition of severe aortic stenosis?
Jet velocity >4.0, Mean gradient >40mmHg, Valve area
What is the medical management of aortic stenosis?
Report symptoms, repeat echo, antibiotic propphylaxis not usually recommended. No medical treatment to prevent progression.
What is the primary determinant for need for aortic valve replacement?
Symptoms. No treatment for asymptomatic patient unless LV dysfunction.
What related condition should be treated with aortic stenosis?
Left ventricular dysfunction. Treat with ACE inhibitors but need to be careful with increasing vasodilation not to reach syncope.
Without treatment, what is the prognosis for severe aortic stenosis?
Almost half die within a year of onset of symptoms.
What is the surgical treatment for aortic valve stenosis that is not calcified?
Commissurotomy (separate cusps of valves) or balloon valvuloplasty. Not for severe cases.
What is the surgical treatment for aortic valve stenosis that is calcified?
Aortic valve replacement (AVR) or Percutaneous/transapical valve implantation.
What is the Ross procedure for AVR?
Remove stenosed aortic valve, take pulmonic valve into aortic and replace pulmonic valve with artificial valve.
Why is a Ross procedure performed?
Pulmonic artificial valves last a while.
When are mechanical valves used over biologic valves?
Aortic prosthesis don’t last very long. In young patient, biological prostehsis last 12-15 years and then degenerate. In young patient insert mechanical because last longer. In elderly give biological (porcine) valve because life expectancy is less than valve expectancy.
What is percutaneous/transapical valve implantation?
Stented valve inserted via catheter while dilating old valve. Treatment for older patients that can’t tolerate surgery (not as good as surgery).
Which is more common, aortic stenosis or regurgitation?
Stenosis.
What is the prevalnce of aortic stenosis?
Approximately 2% of people over the age of 65, 3% of people over age 75, and 4% percent of people over age 85 have aortic valve stenosis.
What is the etiology and pathology of aortic regurgitation?
Valvular disease (congenital or acquired), aortic root disease (usually Marfan syndrome)
What is the most common etiology of aortic regurgitation?
Hypertension (but since so ubiquitous, no prognostic implication, many with very little regurgitation)
Pathophysiology of aortic regurgitation
Increased LVEDV. Increased effective stroke volume and EF, eccentric hypertrophy, late in course EF declines at rest and ESV increases.
Where does the volume overload come from in aortic regurgitation?
Blood goes back to LV from aorta during diastole, dilates in compensation.
What is the consequence on the LV as a result of longstanding aortic regurgitation?
Dilatation and eccentric hypertrophy.
Why is there LV hypertrophy in aortic regurgitation?
Compensation to maintain CO and increase SV. While compensating, asymptomatic.
What happens late in severe aortic regurgitation after compensation is no longer possible?
EF declines and ESV increases leading to heart failure.
What is the pathophysiology of acute AR?
No LV addaptation, failure of SV to compensate and CO decreases and LVEDV increases rapidly.
What is the consequence of high diastolic pressure in severe aortic regurgitation?
Pulmonary edema, cardiogenic shock. CO doesn’t meet needs.
What are the causes of acute aortic regurgitation?
- Endocarditis, 2. Dissection of ascending aorta (splits valve causing leaking)
Clinical manifestations of chronic severe aortic regurgitation?
Long latent or mildly symptomatic period with progressive LV dilatation-asymptomatic. Symptoms appear after cardiomegaly/CHF and LV dysfunction. Dyspnea and inability to exercise, nocturnal angina (low HR), awareness of heartbeat
Symptoms of severe acute aortic regurgitation
Sudden collapse with severe dyspnea and hypotension. Pulmonary edema or cardiogenic shock. Sweating, may be stuperous.
What are findings in a physical exam of chronic severe AR?
Collapsing pulse, wide pulse pressure in BP, diffuse and dynamic apical impulse (wide and diverted to left), soft S1, A2, S3, early diastolic murmur, Austin-Flint murmur.
What is the murmur generally heard in aortic regurgitation?
Early diastolic, the longer the murmur the more severe the AR.
What is the Austin-Flint murmur?
Rare, diastolic murmur sounding like mitral stenosis without mitral stenosis. Happens in patients with severe AR because a jet of AR closes the mitral valve early. Middiastolic.
What are the clinical signs of acute severe AR?
Patient looks gravely ill, tachycardia, peripheral vasoconstriction, pulmonary congestion and edema, low blood pressure, low pulse pressure/low CO, murmur may not be heard or short early diastolic. S1 decreased, S3 and S4.
Lab/EKG findings in chronic AR
Left axis deviation, signs of volume overload. CXR: cardiomegaly and large LV. Echo shows flow.
Can a small level of aortic regurgitation be normal?
No, always pathological.
Patient management in acute severe AR due to aortic dissection?
Immediate surgery, but while waiting give positive inotropic drugs (adrenaline, dopamine) and vasodilators.
What is the patient management in acute AR due to endocarditis if stable?
Deferred operation and start antibiotics then send for surgery.
What is the patient management in acute AR due to endocarditis if unstable?
Immediate surgery (positive inotropes in the meantime), then antibiotics.
Treatment for chronic AR
Just followup for mild/moderate or mildly dilated LV. If severe without symptoms, vasodilators and followup every 3-6 months. If symptomatic/LV dysfunction, mechanical treatment, need to change valves.
Surgical treatment-valve replacement for AR-indications
If end systolic diameter is >55mm, systolic ejection fraction is
What is a composite graft operation?
Valve with aortic root both replaced (common in Marfan).
