I am going to describe in this ppt how to assess severityy of AR by echo, its advantage and limitation.

1. Assessment of severity of aortic regurgitation by
echocardiography
Presenter
DR PRAVEEN GUPTA
Moderator
DR AJIT ANANTHAKRISHNA
PILLAI
Date - 2/08/2016
Department of Cardiology,
JIPMER
Pondicherry, India

2. Introduction
 Aortic Regurgitation (AR) is diastolic reflux of blood from the aorta
to the LV
Caused by
 Malfunction of the aortic valve leaflets
 Dilation of the aortic root and annulus
 Combination of these factors
 Aortic root disease >50% of all Aortic valve replacement (AVRs)

3. Evaluating the Severity of Aortic Regurgitation
Effective
regurgitant orifice area
Volume or fraction of regurgitant
flow
Size or extent of the regurgitant jet within the LV

4. Evaluating the Severity of Aortic Regurgitation
By Colour flow imaging
 Record jet in multiple imaging
planes to provide a three-
dimensional assessment of its
dimensions
 Area of the jet,estimated by
planimetry.
 Parasternal long-axis view,
the height of the jet just below
the valve measured
 This dimension can also be
expressed as a percentage of
left ventricular outflow tract
dimension to provide an
estimate of severity
Three examples of aortic regurgitation are
provided, all taken from the parasternal long-
axis view using color Doppler. Mild (A),
moderate (B), and severe (C) aortic
regurgitation are illustrated.

5. Evaluating the Severity of Aortic Regurgitation
by colour flow imaging
 The greater the percentage is of the left ventricular outflow tract that is
filled by the jet at its origin, the more severe the regurgitation.
 A jet that occupies > 60% of the LVOT (either height or area) indicates
severe AR.
 A similar approach uses the short-axis view with the imaging plane
positioned immediately proximal to the aortic valve .
 The outflow tract is directly visualized as a circular space, and the
regurgitant jet is visualized as a two-dimensional shape within this circle

6. Using transesophageal echocardiography, the jet can be visualized from the
short-axis view, just below the aortic valve. A: The regurgitant orifice is visualized
with two-dimensional imaging. B: Color Doppler is used to demonstrate flow
within the regurgitant orifice. C: The regurgitant orifice area is measured by
planimetry (0.75 cm2).

7. Evaluating the Severity of Aortic Regurgitation
By Colour flow imaging
A:The schematic demonstrates how the dimensions of the color jet of aortic
regurgitation can be used to estimate severity. B: The jet height just below the aortic
valve (arrows) can be measured and compared with the dimension of the left
ventricular outflow tract. This is a useful measure of severity

8. Evaluating the Severity of Aortic Regurgitation
By colour flow imaging
 Both length of the jet and area of jet method conveys unreliable
information about overall severity.
 The best dimensional predictors of angiographic severity are, jet area
indexed to the LV short-axis area (parasternal short-axis view) and jet
diameter indexed to LVOT diameter immediately proximal to the valve
(paraternal long axis view)

9. Limitations to the use of color flow mapping
 Eccentric jets tends to alter the perception of severity
 Size of the jet is instrument dependent.
 Changes in gain, color scale, transducer frequency, and wall filters
affect the jet appearance
 Jet is greater from an apical view compared with a parasternal view
 Regurgitant orifice area in chronic aortic regurgitation changes (and
usually decreases) during diastole, and it lead to color Doppler to
overestimate severity because the visualized jet area would reflect
peak rather than mean orifice area

10. Vena Contracta
• Narrowest portion of a jet that occurs at or just downstream
from the orifice
• Measure of the effective regurgitant orifice area (EROA)
• Independent of flow rate and driving pressure
• Small errors in measurement lead to a large percent error
and misclassification of the severity of regurgitation

11. Vena Contracta
 Vena contracta width of ≥ 6 mm
correlates well with severe AR
(sensitivity 95%, specificity 90%)
 Vena contracta width of < 3 mm
specific for mild AR.
Enriquez-Sarano M, et al. NEJM
2004; 351: 1539-1546
.

12. Proximal Isovelocity Surface Area (PISA)
by colour flow
 Acceleration of flow occurs proximal
to the valve plane with a series of
isovelocity “surfaces” leading to the
high-velocity jet in the regurgitant
orifice.
 Velocity for a PISA =aliasing velocity
where a distinct red-blue interface
seen (at this interface, velocity is
equivalent to Nyquist limit).
 Surface area of the PISA region is
2πr2

13. Proximal Isovelocity Surface Area
 Peak regurgitant flow
obtained by multiplying
surface area by aliasing
velocity
 Effective regurgitant orifice
area (EROA) is peak
regurgitant flow divided by
peak velocity obtained by CW
Doppler.

14. PISA
Limitations
 Isovelocity contour flattens as it approaches the orifice,
underestimating flow
 Proximal structures can distort the isovelocity contour
 Sensitive to errors in radius measurement
 10% error in radius leads to 21% error in flow
 Multiple measurements
 Technically challenging

15. Evaluating the Severity of Aortic Regurgitation by
Continuous Doppler
 The simplest approach compares the density or darkness of the envelope of the antegrade
aortic flow and the regurgitant jet.
 Mild aortic regurgitation the velocity of the regurgitant jet remains relatively high and
the envelope appears flat.
 With more severe aortic regurgitation, steeper slope of the Doppler envelope.
 The deceleration of jet velocity can be described as either the slope or the pressure
half-time of the jet
 Factors, including aortic compliance, blood pressure, and left ventricular
size and compliance affect these measures

16. Evaluating the Severity of Aortic Regurgitation
by Continuous Wave Doppler
This schematic illustrates how hemodynamic changes are reflected in the Doppler velocity tracing.
Left: Mild aortic regurgitation (AR) is associated with a fairly flat contour of the regurgitant jet.
Right: As severity increases, the slope of the jet becomes steeper. These changes are the result of
the instantaneous pressure gradient between the aorta and left ventricle during diastole

17. Pressure Half-Time
 Rate at which aortic and LV pressures equalize
 Most relaible in the setting of acute regurgitation
 Rapid rate of decline in aortic pressure is reflected in steeper diastolic
deceleration slope
 A pressure half-time less than 250 milliseconds or a slope greater than 400
cm/sec2 are indicators of severe aortic regurgitation

18. Evaluating the Severity of Aortic Regurgitation
Pressure Half-Time
Continuous wave Doppler imaging of the aortic regurgitation (AR) jet permits
quantitation of both slope and pressure half-time (P½t). Top: An example of
mild aortic regurgitation is demonstrated. The slope is relatively flat and the
P½t is long. Bottom: An example of severe aortic regurgitation demonstrates a
much steeper slope and shorter P½t.

19. Pressure Half-Time
 For a given severity of AR, P1/2 will be shortened by elevated LVEDP or
vasodilator therapy that reduces AR
 With acute AR-triangular-shaped CW-Doppler with linear deceleration
slope from maximum velocity to baseline

20. Pressure Half-Time

21. Limitations of pressure half-time assessment
 Pressure half-time sensitive to chronicity of AR
 Acute AR leads to much shorter values than chronic AR when LV is dilated
with increased compliance
 Pressure half-time varies with SVR
 Vasodilators may shorten the pressure half-time even as the aortic
regurgitant fraction improves

22. Evaluating the Severity of Aortic Regurgitation
Regurgitant Volume or Fraction
Pulsed Doppler imaging
 Stroke volume at any valve annulus is derived as the product of CSA and
VTI of flow at the annulus
 In the absence of regurgitation, SV determinations at different sites (LVOT,
mitral annulus, pulmonic annulus) should be equal
 Mild: < 30 cc (< 30%)
 Mild-moderate: 30-44 cc (30-39%)
 Moderately severe: 45-59 cc (40-49%)
 Severe: ≥60 cc (≥50%)

23. Evaluating the Severity of Aortic Regurgitation
Regurgitant Volume or Fraction
Stroke volume can be measured
through any valve within the heart.
This schematic demonstrates how
stroke volume can be calculated at
the level of the aortic valve and
mitral valve . The difference in
stroke volume represents the
regurgitant volume. In addition,
the regurgitant fraction can be
calculated

24. Regurgitant Volume or Fraction
Limitation
 Cannot be used in presence of shunts
 Sensitive to small measurement errors
 Requires multiple measurements,
 Assumes no regurgitation at reference valve
 Limited quantitative information
 Affected by sample volume location

25. Evaluating the Severity of Aortic Regurgitation
Pulsed Doppler imaging
 Severe AR - diastolic flow reversal in the descending aorta
 Nonquantitative approach using pulsed Doppler imaging
 Presence of holodiastolic flow reversal in the descending aorta has been
correlated with severe aortic regurgitation
 False positives may occur if a PDA is present
 This parameter is dependent on vessel compliance and the location of the
sample volume

26. Evaluating the Severity of Aortic Regurgitation
by M-mode echocardiography and two-dimensional imaging
 End-diastolic
 End-systolic LV dimensions
 Ejection fraction
 Fractional shortening
 End-systolic wall stress
 LV systolic dysfunction
 Increase in end-systolic
dimension

27. Criteria for Severe AR
 Jet width >_65% of LVOT
 Vena contracta >0.6 cm
 Holodiastolic flow reversal in the proximal abdominal aorta
 Rvol>_60 ml/beat
 RF>50%
 ERO>_0.3 cm2
 Angiography grade 3+ to 4+
 Evidence of LV dilation

28. Take Home Message
 The best dimensional predictors of angiographic severity are jet area
indexed to the LV short-axis area (parasternal short-axis view) and jet
diameter indexed to LVOT diameter immediately proximal to the valve
(paraternal long axis view)
 Jet length is not a reliable index of severity
 The pressure half-time is most relaible in the setting of acute regurgitation
 Holodiastolic flow reversal is a marker of at least moderate regurgitation

29. References
• Recommendations for Evaluation of the Severity of Native Valvular
Regurgitation with Two-dimensional and Doppler Echocardiography, A
report from the American Society of Echocardiography’s Nomenclature
and Standards Committee and The Task Force on Valvular Regurgitation
• Feigenbaum's Echocardiography, 6th Edition, Feigenbaum, Harvey;
Armstrong, William F.; Ryan, Thomas,Copyright ©2005 Lippincott
Williams & Wilkins
• Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 10th
Edition