Aortic Stenosis summary Flashcards
Causes and Pathophysiology of Aortic Stenosis
Senile: wear and tear, fibrosis/calcification of valve - most common
Bicuspid: congenital, 2/3 cusps are fused (at raphe), wear out faster - commonest in <65
Rheumatic: damage and fusion from rheumatic fever, mitral also damaged
High LVP required to pump through narrow AV - stiff - higher LAP, more O2 needed - poorer diastolic filling, A fib. LV dilation
Describe clinical syndromes of Aortic Stenosis
Long asymptomatic phase, then very short downward phase after onset: Symptom 50% mortality Angina → 5 years Syncope → 3 years Heart failure → 2 years Atrial fib. → 0.5 years
Symptoms of Aortic Stenosis
SAD
Syncope: cardiac output is maxed, so BP can’t increase when exercising or when vascular resistance lower (BP = CO x VR).
Angina: thick muscle needs lots of O2, poorer backflow (LVP ~ Aortic P)
Dyspnea: classic LAP, pulm. edema, etc.
Signs and Physical findings of Aortic Stenosis
BP usually normal, HR normal (except A fib.)
Precordium:
-Apex normal (sustained), can be displaced with LVH
-Palpable S4 or AS thrill
Heart sounds:
-S2 weaker, A2 delayed (paradoxical), S3 if LV fails
-Diamond (cres. - decres.) systolic murmur (peaks later the more severe) - radiate to carotid
Pulse:
Parvus et tardus (low and slow) carotid pulse - Atherosclerosis can mask it
Key lab tests and findings of Aortic Stenosis
ECG: LVH signs common (+/- LA enlargement)
Echocardiogram (best): see leaflets (#, mobility); measure of AV area; LV size, thickness, function; assess all other valves
Cardiac catheterization: LV and Ao pressures → estimate severity of AS; Can do AV area to resolve discrepant results; check CAD before surgery (unless very young)
Tx of Aortic Stenosis
No drugs. Avoid exertion. Good oral hygiene (endocarditis risk).
Sx: tissue or metal valve replacement (open heart or transcutaneous)
