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

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

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

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

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

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

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

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

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

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

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

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

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

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

AR – 2D Imaging

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

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

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:

AR MS

Presence of mitral stenosis or mechanical mitral valve

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%

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

Echo assessment: Vena Contracta Measurement of the most narrow portion of jet behind the valve. Mild: <3.0mm Moderate: 3.0-5.9mm Severe: >=6.0mm Enriquez-Sarano et al. Aortic Regurgitation. NEJM; 351:1539-46.

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: 2000. 17; 294-302

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

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

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:2000. 17; 294-302

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

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.

AR- Regurtitant volume

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%)

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

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

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

Summary

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.

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.

AR – Surgical Indications