1. Echo Conference Aortic Regurgitation
September, 2007
Christopher Dibble, M.D.

2. Aortic Regurgitation: Symptoms
Dyspnea, orthopnea, PND
Chest pain.
Nocturnal angina >> exertional angina
( diastolic aortic pressure and increased LVEDP thus  coronary artery diastolic flow)
With extreme reductions in diastolic pressures (e.g. < 40) may see angina

3. Peripheral Signs of Severe Aortic Regurgitation
Quincke’s sign: capillary pulsation
Corrigan’s sign: water hammer pulse
Bisferiens pulse (AS/AR > AR)
De Musset’s sign: systolic head bobbing
Mueller’s sign: systolic pulsation of uvula
Durosier’s sign: femoral retrograde bruits
Traube’s sign: pistol shot femorals
Hill’s sign:BP Lower extremity >BP Upper extremity by
> 20 mm Hg - mild AR
> 40 mm Hg – mod AR
> 60 mm Hg – severe AR

4. Aortic Regurgitation Can be a caused by: Valve Disease
Aortic root disease
Percentage of aortic root disease steadily increasing over past few decades
Root disease now accounts for >50% of all AVRs

5. AR – Valvular disease Rheumatic disease Calcific AS
Cusps become fibrotic and retract
Usually also stenotic
MV is involved
Calcific AS
At least mild AR in 75% of patients

6. AR – Valvular disease II
Infective endocarditis
Leaflet perforation
Vegetation interferes with coaptation
Trauma
Bicuspid Valve
Can isolated regurgitation or stenosis, or both
Complication of catheter based ablation

7. AR – Valvular disease III
Myxomatous degeneration
Structural deterioration of bioprosthesis
Less common causes:
SLE, RA
Ankylosing spondylitis
Jaccoud arthropathy
Takayasu disease
Whipple’s disease
Anorectic drugs
Congential (rare, usually associated with bicuspid valve)
Membranous subaortic stenosis

8. Aortic root disease
Dilation here is common; especially in AS; does not lead to AR
Between aorta proper and the annulus is a tube composed of collagen that forms sinuses of valsalva
As little as 2mm of dilation here can cause AR
Dilation here is rare

9. Aortic root disease
Dilation of the aortic ridge eliminates the normal overlap of the valves

10. AR – Aortic Root Disease
Age related (degenerative)
Systemic Hypertension
Aortic dissection
Cystic medial necrosis
either isolated or associated with Marphan syndrome
Bicuspid valve

11. AR – Aortic Root Disease II
Syphilitic aortitis
Osteogenesis imperfecta
Ankylosing spondylitis
Relapsing polychondritis
Ehlers-Danlos
Inflammatory bowel disease

12. AR – M-Mode
As the aortic jet cascades across the anterior MV leaflet it can create a high frequency fluttering
In acute AR premature closure of the MV can be seen
Due to rapidly increasing LV pressure

13. AR - M-mode Fluttering of Anterior Mitral Valve leaflet
Increased duration between E and A peaks
Early example of using M-mode to indirectly assess valve disease

14. AR – 2D imaging Detailed evaluation of valve and root
Detailed evaluation of LV size and function
Many important causes of AR easily seen on 2D evaluation
Even when AR is severe, sometimes 2D imaging is suprisingly normal

15. AR – 2D Imaging

18. AR – Doppler Evaluation
Pulsed, continuous wave, and color flow Doppler are highly sensitive for detection of regurgitation and are complementary studies

19. Use of Doppler to Detect Regurgitant Jets
Most regurgitant jets >1.5 m/sec
CW lacks spatial resolution
PW needed to map location and direction of jet
Mitral Inflow
Identifies turbulence in an area; color flow derived from PW data
Helpful for flow profile; gradient

20. AR – Pulsed Doppler
Early to assess severity of AR used pulsed Doppler to “map” AR
sample volume withdrawn towards apex to find length of regurgitant jet
Relies on turbulence during diastole on LV outflow side of AV
This assumes jet is centrally located and can be tracked towards apex
Another possible source of error:

21. AR MS

23. Presence of mitral stenosis or mechanical mitral valve

24. AR – Color Flow Most common technique Sensitivity >95%
False positive negatives; occur in tachycardia with mild AR
Frame rate allows only a few diastolic frames to be displayed
Can be overcome by using CW which has higher sampling rate
Specificity ~100%

25. AR – Color flow Doppler Detects even trivial AR
1% of subjects under 40 y.o.
10-20% of patients greater than 60 y.o

26. Echo assessment: Vena Contracta
Measurement of the most narrow portion of jet behind the valve.
Mild: <3.0mm
Moderate: mm
Severe: >=6.0mm
Enriquez-Sarano et al. Aortic Regurgitation. NEJM; 351:

27. Echo assessment: Jet / LVOT height
Jet height to LVOT height ratio
Mild: 1-24%
Moderate: 25-46%
Moderate-severe: 47-64%
Severe: >=65%
Limitations:
Lateral resolution of color Doppler
Sensitive to angulation of ultrasound transducer
Ekery, DL et al. Aortic Regurgitation: Quantitative Methods by Echocardiography.
Echocardiography: ;

28. AR – Continuous wave doppler
Because AR jet is high velocity, CW Doppler necessary to record envelope of jet.
The density of the jet compared with antegrade aortic flow is a (very simple) qualitative indication of the volume of regurgitation

29. AR – Continuous wave doppler
Antegrade
Density is function of number of blood cells sampled and will generally increase with the regurgitant volume

30. AR – CW Doppler
Retrograde
Antegrade
Aortic regurgitant fraction can be estimated by ratio of reversed flow VTI / forward flow VTI in the distal aortic arch.
Ekery, DL et al. Aortic Regurgitation: Quantitative Methods by Echocardiography.
Echocardiography: ;

31. AR – Continuous wave doppler
Absolute gradient does not closely reflect amount of AR
Severity of AR can be described by the slope or the pressure half time
Pressure half time of less than 250 msec is an indicator of severe AR

32. AR - pressure half-time
Limitations:
Pressure half-time sensitive to chronicity of AR
acute AR leads to much shorter values than chronic AR when ventricle is dilated with increased compliance and can accommodate large regurgitant volumes.
Pressure half-time varies with systemic vascular resistance
vasodilators may shorten the pressure half-time even as the aortic regurgitant fraction improves.

33. AR- Regurtitant volume

34. AR - Regurgitant Volume or Fraction
Compare flow through aortic valve versus mitral or pulmonary valve.
Regurgitant volume (fraction):
Mild: <30cc (<30%)
Mild to moderate: 30-44cc (30-39%)
Moderately severe: 45-59cc (40-49)
Severe: >=60cc (>=50%)

35. AR - Regurgitant Volume or Fraction
Limitations:
Assumes normal flow through comparison valve.
Cannot be used in presence of shunts.
Sensitive to small measurement errors.

36. AR - Proximal isovelocity surface area
The PISA method can estimate regurgitant flow rate, and subsequently regurgitant orifice area).

37. AR - Proximal isovelocity surface area
Limitations of PISA
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

38. Summary

39. Severe AR - Surgical Indications
Symptomatic patients (dyspnea or angina)
Normal, mildly depressed or moderately depressed LV
Surgery.
Severely depressed or dilated LV (EF<25% or LVESD>60mm)
High surgical risk (~10% operative mortality) but also poor outcomes with medical therapy.

40. Asymptomatic Severe AR - Surgical Indications
Preserved LV
Observe with serial echocardiograms.
Abnormal LV
“Rule of 55”: Surgery if:
LVEF <55% (ACC/AHA guidelines <50%)
LVESD > 55mm (or > 25 mm/m2).
Also surgery if LVEDD >70-75 mm
Uncertainty on which combination of criteria most useful.

41. AR – Surgical Indications