Aortic Stenosis Echocardiography
OVERVIEW
Obstruction can be
- supravalvular
- valvular (most common)
- subvalvular
SEVERITY ASSESSMENT
- appearance
- mobility
- gradient
— continuous wave Doppler allows peak velocity to be measured -> peak gradient can be calculated using Bernoulli equation
— peak gradient = 4 x peak velocity across the narrowing squared
— normal peak gradient < 10mmHg, critical > 70mmHg
— gradient measurements are very dependent on ventricular function so can be misleading. - area
— normal 2.5-5.5 cm2
— critical < 0.92 cm2 - dimensionless severity index = ratio of LVOT velocity/aortic valve velocity (V1/V2)
— provides a dimensionless measurement of aortic stenosis which is independent of Q
— < 0.25 implies a valve area of 0.75cm2 (severe AS) - complications:
— LV hypertrophy or dilation
— LV systolic and diastolic dysfunction
— post-stenotic dilation
CATEGORIES OF AORTIC STENOSIS SEVERITY
From Vahanian et al, 2010:
References and links
Journal articles
- Vahanian A, Otto CM. Risk stratification of patients with aortic stenosis. Eur Heart J. 2010 Feb;31(4):416-23. PMID: 20047994
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at The Alfred ICU, where he is Deputy Director (Education). He is a Clinical Adjunct Associate Professor at Monash University, the Lead for the Clinician Educator Incubator programme, and a CICM First Part Examiner.
He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. He was one of the founders of the FOAM movement (Free Open-Access Medical education) has been recognised for his contributions to education with awards from ANZICS, ANZAHPE, and ACEM.
His one great achievement is being the father of three amazing children.
On Bluesky, he is @precordialthump.bsky.social and on the site that Elon has screwed up, he is @precordialthump.
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