Echo assessment of Aortic Regurgitation

Echocardiographic Assessment of AR

Dr. Md. Mashiul AlamPhase B resident

Chairperson: Assoc. Prof. N. Sheikh

Aortic valve anatomy

• 3 cusp, 3 commisure• 3-4 cm sq

RCC

NCC

NoRmaL – clock wise

Common Causes of AR

• Bicuspid aortic valve• Rheumatic disease• Calcific degeneration• Infective endocarditis• Idiopathic aortic dilatation• Myxomatous degeneration• Dissection of the ascending aorta

Options

• TTE

• TEE

• 3D echocardiography

Echocardiographic Views

• PLAX• PSAX at the level of great vessels• Apical views – A4CV, Apical long axis views

Aim of echocardiographic evaluation

• Define the cause of stenosis• Quantification of severity• Evaluation of co existing valvular lesions• Assessment of LV systolic function• Detection of response of chronic volume load

over cardiac chambers

2 D assessment of AR

• Leaflets Prolapse Number Vegetation Calcification

PSAX view

Vegetation

Calcification

• Aortic rootDilation?18-40 yrs: 0.97+(1.12 BSA)>40yrs:1.92+(0.74 BSA)Always abnormal If > 5 cm

Any dissection?In PLAX, PSAX, Suprasternal view

• Left ventricular dimension and functionIn chronic ARLVESD <50-55 mmLVEDD <70-75 mmEccentric hypertrophyLVEF <50%

Acute AR normal dimension and hyperdynamic LV

Doppler Assessment of AR(Qualitative)

• Color doppler jet widthColor jet width vs LVOT width in PLAX or PSAX viewOverestimated in apical viewsMild AR <25%Severe AR ≥65 %

Length of AR jet should not be used to assess AR severity

• Vena contracta widthReflects diameter of regurgitant orificeAvoids erroneous measurement of jet when it

expands in LVOTPLAX or PSAX zoomed viewMild AR < 0.3 cmSevere AR> 0.6 cm

Three componentsOf regurgitant jet:1. PFC2. VC3. Broadening in LVOT

• Pressure half time (PHT)CW doppler in Apical three or five chamber

viewsMild AR >500 msSevere AR < 200 ms

Density of signal of doppler envelope also a sign of severity

Steeper issevere

• Diastolic flow reversal in aortaPW doppler in suprasternal (descending thoracic

aorta) or subcostal (abdominal aorta) viewECG gated echo needed

Holodiastolic flow reversal is abnormal. Brief flow reversal may be present normally.

Doppler Assessemnt of AR(Quantitative)

Not frequently doneOften be determined by combination of

qualitative methods and 2D assessmentOptions:PISA (Proximal Isovelocity Surface Area)Regurgitant volumeRegurgitant fractionEffective regurgitant orifice area (EROA)

PISA

It’s the surface area of blood moving back from the aorta towards the closed aortic valve at the given aliasing velocity

Zoomed A3CV or A5CVDecreasing the depthNarrow sector

PISA = 2πr2

• Regurgitant Volume =Volume of blood that regurgitates across the valve

per beatVolumes calculated according to continuity equation RegrugV = SV total – SV forwardSV total = Transaortic volume =CSA LVOT x VTI LVOTSV forward = Transmitral volume = CSA mitral

annulus x VTI mitral annulus

• SV total can be measure by LVEDV – LEVSV (Simpsons method)

• For SV forward or transmitral volume PW doppler at the level of MV; should be used not at mitral tip

Regurg. Volume calculated by PISA method

Regurg Volume = EROA x VTI AR jet

Mild AR < 30ml/ beat Severe AR ≥ 60ml/ beat

• Regurgitation fraction = Regurg V/ SV total

Mild AR < 30 %Severe AR ≥ 50%

• EROA (Effective regurgitation orifice area)

= PISA x aliasing velocity / AR Vmax or = Regurg V / VTI AR jet

Mild AR < 0.1 cm sq. Severe ≥ 0.3 cm sq.

TEE in AR

• Complement TTE• Better visualization of valve morphology and

aortic root dimensions e.g., Endocarditis Aortic dissection

Indirect sign of AR

• Increased EPSS• Fluttering of mitral leaflet• Reverse doming of the anterior mitral leaflet

Associated valvular lesion in AR

• Aortic stenosis• Mitral stenosis or mitral regurgitation• MAC