Aortic Stenosis Flashcards
What are the three causes of valvular stenosis?
Congenital Abnormality
Post inflammatory process (rheumatic)
Degenerative Calcification
In isolated stenosis, when do clinical symptoms typically occur?
when the orifice is reduced to 1/4 its normal size
In mixed stenosis, when do clinical symptoms typically occur?
When each is moderate
What is the ventricular response to pressure overload?
hypertrophy
What is the atrial response to pressure overload?
dilation
What is the ventricular response to volume overload?
dilation
Chronis pressure overload can lead to irreversible changes where?
in proximal chambers including the pulmonary vascular bed
What does a complete echo evaluation of valvular stenosis include?
Imaging of the valve to determine etiology
Quantification of stenosis severity
Evaluation of coexisting valvular lesions
Assessment of left ventricular systolic function
Response of chronic overload on proximal chambers and vascular bed
Aortic Stenosis Echo Findings
Thickened leaflets Restricted leaflet motion (with lack of normal systolic fluttering) Reduced AV orifice in systole Reduced ACS AI (found in 80%) LVH LAE Decrease LVSF late in course Post-stenotic dilation of the ascending aorta
What are the signs of inadequate cardiac output?
Dyspnea/DOE is the most common symptom Anginal chest pain (35%) Effort dizziness/syncope (15%) Hypotension Fatigue
What are the signs of overload to pulmonary venous system?
Dyspnea/DOE Orthopnea PND Cough Rales or crackles Sputum
What are the signs of overload to the right heart and cava?
Jugular venous distension Hepatomegaly (enlarged liver) Right upper quadrant pain Ascites (fluid in abdomen) Peripheral edema
What auscultation is associated with AS?
harsh mid systolic ejection murmur heard at Right Upper Sternal Border
crescendo-decrescendo
softened S2 (CA+ muffles snap)
also an S4 (decreased LV compliance)
What palpitation is associated with AS?
Pulsus parvus et tardus = rises slowly and is small and sustained
best heard at right carotid artery
What cath measurement has no echo equivalent?
Peak to Peak PG
What findings associated with AS will be present on an EKG?
LVH
LAE
What complications are associated with AS?
Increased risk of syncope and low SBP (narrow pulse pressure= difference between systolic and diastolic BP)
Lethal arrhythmia
Endocarditis
Systemic embolus
How would you treat AS?
Monitor symptoms and degree of stenosis to time AV replacement (activity restriction) AV Replacement (typically open heart surgery)
What possible medications would ease symptoms in heart failure?
Diuretics (decrease volume) Beta Blockers (slow rate and O2 demand) Nitrates (dilate coronaries and increase O2 delivery)
What possible medications would they use to treat AS?
Prophylactic antibiotics if deemed necessary
Controlled BP and lipid lowering drugs may slow progression
Etiologies and 2D findings:
Degenerative Calcification
- most common cause of AS
- calcification occurs over many years, reducing the systolic opening
- tends to present itself at age 70-85 (senile)
- 2D PSAX: valve very echogenic and filled in
- Reduced ACS
- Normally on M-mode AV cusps flutter when opening but NOT in AS
What is aortic sclerosis?
Valve calcification without stenosis or borderline stenosis
Where is the degree of stenosis determined?
CW/PW Doppler
Etiologies and 2D Findings:
Congenital Bicuspid
- most common congenital AS
- symptoms present at age 45-65
- 2D PSAX Diastole: valve can look normal/tri due to the presence of raphe
- 2D PSAX Systole: best identified as an oval or football shaped opening (not triangle)
- 2D PLAX: systolic/diastolic bowing/doming of leaflets into the aorta is a helpful identifier
- M-Mode: may show eccentric closure line
- May become calcific and stenosed, then harder to ID
- also look for AI, dilation of sinuses, and AR
