ECHO 2013 / Aortic Stenosis Quantitation It’s Not All About the Gradient
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Aortic Stenosis Quantitation:
It’s not all about gradient
Philippe Pibarot, DVM, PhD, FACC, FAHA, FESC, FASE Canada Research Chair in Valvular Heart Diseases
Institut Universitaire de Cardiologie et de Pneumologie de Québec / Québec Heart & Lung Institute
Université
LAVAL
Disclosure Statement
Edwards Life Sc: Research Grant
Indication for AVR in AS
SEVERE STENOSIS |
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Peak aortic jet velocity |
≥ 4 m/s |
Mean gradient: |
≥ 40 mmHg |
Aortic valve area (AVA): |
≤ 1.0 cm2 |
Indexed AVA: |
≤ 0.6 cm2/m2 |
+ SYMPOMS |
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± LVEF<50% |
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= AVR (Class I) |
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Quantitation of AS Severity:
Look at the Valve, the Aorta/Arteries,
&the Ventricle
Valvular load
Arterial load
Total (V+A)
LV hemodynamic load
LV function and outflow
Look at the Valve
►Assessing Valvular Load
►Predicting Rapid Stenosis Progression
Conventional Parameters of AS Severity:
Peak Aortic Jet Velocity and Mean Gradient
Otto NEJM 2008
Peak Jet Velocity: A Powerful Predictor
of Outcomes
Baseline Stenosis Severity |
Rapid Stenosis Progression |
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(≥0.3 m/s/yr) |
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Otto CM et al. Circulation. 95:2262-2270, 1997
Rosenhek et al N Engl J Med 2000; 343:611-7
Peak Jet Velocity and Gradient are Highly Flow-Dependent
Severe AS
Low Flow
Normal
Flow
∆P
VPeak
Valve Effective Orifice Area
AOA
EOA
AS Severity
Mild |
> 1.5 cm2 |
Moderate |
1.0-1.5 cm2 |
Severe |
< 1.0 cm2 |
LVOT |
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LVOT |
Aortic |
diameter |
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velocity |
Jet velocity |
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CSALVOT VTILVOT |
VTIAo |
AVA =
(CSALVOT×VTILVOT)
VTIAo
CONTINUITY
EQUATION
Measurement Errors: LVOT Diameter
Underestimation of LVOTD
Poor accoustic window
Image truncated
LVOT elliptical
Overestimation of LVOTD
Too far in the LV
Oblique measure