2Aortic Regurgitation: Symptoms Dyspnea, orthopnea, PNDChest 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
3Peripheral Signs of Severe Aortic Regurgitation Quincke’s sign: capillary pulsationCorrigan’s sign: water hammer pulseBisferiens pulse (AS/AR > AR)De Musset’s sign: systolic head bobbingMueller’s sign: systolic pulsation of uvulaDurosier’s sign: femoral retrograde bruitsTraube’s sign: pistol shot femoralsHill’s sign:BP Lower extremity >BP Upper extremity by> 20 mm Hg - mild AR> 40 mm Hg – mod AR> 60 mm Hg – severe AR
4Aortic Regurgitation Can be a caused by: Valve Disease Aortic root diseasePercentage of aortic root disease steadily increasing over past few decadesRoot disease now accounts for >50% of all AVRs
5AR – Valvular disease Rheumatic disease Calcific AS Cusps become fibrotic and retractUsually also stenoticMV is involvedCalcific ASAt least mild AR in 75% of patients
6AR – Valvular disease II Infective endocarditisLeaflet perforationVegetation interferes with coaptationTraumaBicuspid ValveCan isolated regurgitation or stenosis, or bothComplication of catheter based ablation
7AR – Valvular disease III Myxomatous degenerationStructural deterioration of bioprosthesisLess common causes:SLE, RAAnkylosing spondylitisJaccoud arthropathyTakayasu diseaseWhipple’s diseaseAnorectic drugsCongential (rare, usually associated with bicuspid valve)Membranous subaortic stenosis
8Aortic root diseaseDilation here is common; especially in AS; does not lead to ARBetween aorta proper and the annulus is a tube composed of collagen that forms sinuses of valsalvaAs little as 2mm of dilation here can cause ARDilation here is rare
9Aortic root diseaseDilation of the aortic ridge eliminates the normal overlap of the valves
10AR – Aortic Root Disease Age related (degenerative)Systemic HypertensionAortic dissectionCystic medial necrosiseither isolated or associated with Marphan syndromeBicuspid valve
12AR – M-ModeAs the aortic jet cascades across the anterior MV leaflet it can create a high frequency flutteringIn acute AR premature closure of the MV can be seenDue to rapidly increasing LV pressure
13AR - M-mode Fluttering of Anterior Mitral Valve leaflet Increased duration between E and A peaksEarly example of using M-mode to indirectly assess valve disease
14AR – 2D imaging Detailed evaluation of valve and root Detailed evaluation of LV size and functionMany important causes of AR easily seen on 2D evaluationEven when AR is severe, sometimes 2D imaging is suprisingly normal
18AR – Doppler Evaluation Pulsed, continuous wave, and color flow Doppler are highly sensitive for detection of regurgitation and are complementary studies
19Use of Doppler to Detect Regurgitant Jets Most regurgitant jets >1.5 m/secCW lacks spatial resolutionPW needed to map location and direction of jetMitral InflowIdentifies turbulence in an area; color flow derived from PW dataHelpful for flow profile; gradient
20AR – Pulsed DopplerEarly to assess severity of AR used pulsed Doppler to “map” ARsample volume withdrawn towards apex to find length of regurgitant jetRelies on turbulence during diastole on LV outflow side of AVThis assumes jet is centrally located and can be tracked towards apexAnother possible source of error:
23Presence of mitral stenosis or mechanical mitral valve
24AR – Color Flow Most common technique Sensitivity >95% False positive negatives; occur in tachycardia with mild ARFrame rate allows only a few diastolic frames to be displayedCan be overcome by using CW which has higher sampling rateSpecificity ~100%
25AR – Color flow Doppler Detects even trivial AR 1% of subjects under 40 y.o.10-20% of patients greater than 60 y.o
26Echo assessment: Vena Contracta Measurement of the most narrow portion of jet behind the valve.Mild: <3.0mmModerate: mmSevere: >=6.0mmEnriquez-Sarano et al. Aortic Regurgitation. NEJM; 351:
27Echo assessment: Jet / LVOT height Jet height to LVOT height ratioMild: 1-24%Moderate: 25-46%Moderate-severe: 47-64%Severe: >=65%Limitations:Lateral resolution of color DopplerSensitive to angulation of ultrasound transducerEkery, DL et al. Aortic Regurgitation: Quantitative Methods by Echocardiography.Echocardiography: ;
28AR – 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
29AR – Continuous wave doppler AntegradeDensity is function of number of blood cells sampled and will generally increase with the regurgitant volume
30AR – CW DopplerRetrogradeAntegradeAortic 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: ;
31AR – Continuous wave doppler Absolute gradient does not closely reflect amount of ARSeverity of AR can be described by the slope or the pressure half timePressure half time of less than 250 msec is an indicator of severe AR
32AR - pressure half-time Limitations:Pressure half-time sensitive to chronicity of ARacute 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 resistancevasodilators may shorten the pressure half-time even as the aortic regurgitant fraction improves.
34AR - 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%)
35AR - Regurgitant Volume or Fraction Limitations:Assumes normal flow through comparison valve.Cannot be used in presence of shunts.Sensitive to small measurement errors.
36AR - Proximal isovelocity surface area The PISA method can estimate regurgitant flow rate, and subsequently regurgitant orifice area).
37AR - Proximal isovelocity surface area Limitations of PISAIsovelocity contour flattens as it approaches the orifice, underestimating flow.Proximal structures can distort the isovelocity contour.Sensitive to errors in radius measurement10% error in radius leads to 21% error in flow
39Severe AR - Surgical Indications Symptomatic patients (dyspnea or angina)Normal, mildly depressed or moderately depressed LVSurgery.Severely depressed or dilated LV (EF<25% or LVESD>60mm)High surgical risk (~10% operative mortality) but also poor outcomes with medical therapy.
40Asymptomatic Severe AR - Surgical Indications Preserved LVObserve 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 mmUncertainty on which combination of criteria most useful.