7 Carpentier classification Type I = normal leaflet motion but with annular dilatation or leaflet perforationType II = leaflet prolapse (eg myxomatous disease) or papillary muscle ruptureType III = restricted leaflet motion.IIIa = rheumatic diseaseIIIb = ischemic or idiopathic cardiomyopathy.
8 2D Echocardiography: additional information Left ventricular size and function and left atrial size as clues to:- severity of MR- acuteness or chronicity- necessity and timing of surgery
9 Mitral valve prolapseOccurs in 2.4% of the population (Freed at al. NEJM 1999)Patients exhibit fibromyxomatous changes in the mitral leaflettissue that cause superior displacement of the leaflets intothe left atrium (by definition > 2 mm)The most common primary cause of isolated MRrequiring surgical repairBoth familial (loci identified: chromosomes 11, 16, 13)and “sporadic” cases observed
12 Mitral valve prolapseLeaflet elongation can manifest itself not only by superior motion into the LA but also by anterior motion that shifts the coaptation point toward the aortic root and septum.ANTERIORSeptumSeptumAOAOChromosome 13 study: while phenotyping family members we observed that….This has led to the identification of a “prodromal form” or form frusteLVAACoaptationPSUPERIORNormalMVP3
13 Nesta et al. Circulation 2005 Interestingly, these individuals were all carriers of the locusNesta et al. Circulation 2005
14 Prodromal form Anterior displacement of the coaptation point. Mild bulging of the posterior leaflet relative to the anterior.NormalProdromal
15 Functional Mitral Regurgitation: Incomplete Mitral Leaflet Closure IMI or global LVDNORMALMRPapillary Muscle DisplacementMitral ValveTetheringIMLCLVFig 2. Left panel depicts normal mitral valve geometry. Right panel shows restricted leaflet closure termed incomplete mitral leaflet closure. Several mechanisms have been proposed, including abnormal tethering of the mitral valve by displacement of the papillary muscles in the ischemic territory and by annular dilatation.LAAOCourtesy of Judy Hung, MD3
21 MR related to HOCMLV ejection through an LVOT narrowed by both septal hypertrophy and anterior displacement of MV apparatus (PM + MV) causes the Venturi effect or “drag forces” which drag the MV leaflets and chordae towards the septumMR is related to SAM of the anterior mitral leaflet AND failure of post leaflet to move anteriorly with consequent gap between the two leaflets
22 Yu et al. Mitral regurgitation in hypertrophic cardiomyopathy: relationship to obstruction and relief with myectomy. J Am Coll Cardiol 2000;36;
23 Doppler Methods for assessment of severity Color flow Doppler- Regurgitant jet area- Vena contracta- Flow convergence (PISA)Continuous wave DopplerPulsed Doppler- Mitral inflow pattern- Quantitative parameters (regurgitant volume, fraction, EROA)
24 Regurgitant jet area Pros: - Simple, quick screen for mild or severe central MR- Evaluates spatial orientation of jetCons:- Subject to technical, hemodynamic variation- Underestimates severity in eccentric jetsMild: < 4 cm2 or < 20% of LA areaModerate: variableSevere: > 10 cm2 or > 40% of LA areaSmall central jetLarge central jet or variable size wall-impinging jet
25 Vena contracta width SAX LAX Mild: < 0.3 cm Narrowest portion of a jet that occurs at or just downstream from the orifice. The examiner must search in multiple planes perpendicular to the commissural line (such as the PLA view). Widths are not additive, but their cross sectional areas (in SAX view) areMild: < 0.3 cmSevere 0.7 with large central jet or with wall impinging jet of any size
26 Proximal isovelocity surface area (PISA) Based on the hydrodynamic principle that the flow profile of blood approaching a circular orifice forms concentric, hemispheric shells of increasing velocity and decreasing surface area.Color flow mapping able to image one of these hemispheres that corresponds to the aliasing velocity or Nyquist limit of the instrument.The aliasing velocity should be adjusted to identify a flow convergence region with a hemispheric shape.
27 Reg volume = EROA x VTIreg jet PkVreg = the peak velocity of the regurgitant jet by continuous wave DopplerReg volume = EROA x VTIreg jetThe radius of the hemisphere is then measured…The regurgitant volume can be estimated as EROA multiplied by the velocitiy time integral of the regurgitant jetSince PISA calculation provides an instantaneous peak flow rate, EROA is the maximal EROA
28 Proximal isovelocity surface area (PISA) Mild: EROA <0.2cm2Severe: EROA >/=0.4cm2Pros:- Presence of flow convergence at Nyquist limit of cm/s alerts to significant MR- Provides both lesion severity (EROA) and volume overload (R Vol)Cons:- Less accurate in eccentric jets- Not valid in multiple jets- Any error is determining the location/radius of the orifice is squaredTherefore PISA is more accurate if the aliasing velocity can be adjusted to obtain a radius of >/=1cm.
29 Example of PISA calculation r = 0.8 cmRadius is 0.8, the color Doppler scale has been shifted down so that the MR aliasing velocity has been reduced to 36 cm/s, thus maximizing resolution for measuring the aliasing radiusEROA = [6.28 x (.8)(.8) ml/s x 36] / [480 cm/s] = 0.3cm2
30 Supportive signs of MR severity Example of findings of continuous wave (CW) Doppler recordings and pulmonary vein flow bypulsed Doppler in a case with mild and another with severe mitral regurgitation (MR). In mild MR,spectral recording of the jet has a soft density with a parabolic, rounded contour of the regurgitant velocitywhereas in severe MR, the jet is dense with a triangular, early peaking of the velocity (arrow). Pulmonaryvein flow is normal in mild MR with predominance of systolic flow (S). In contrast, the case with severeMR displays systolic flow reversal. D, Diastolic flow velocity.
31 Other supportive signs of MR severity Mild MR:- A-wave dominant mitral inflow **- Normal LV sizeSevere MR:- E-wave dominant mitral inflow (E > 1.2 m/s) **- Enlarged LV and LA size** Usually above 50 years or in conditions of impaired relaxation, in the absence of mitral stenosis or other causes of elevated LA pressureGreater E because of increased diastolic flow
32 Quantitative pulsed Doppler parameters annIn the absence of regurgitation, stroke volume should be equal at different sites, e.g. the mitral and aortic annulus.In the presence of regurgitation (assuming the absence of an intracardiac shunt), the flow through the affected valve is larger than through other competent valves.Stroke volume = product of CSA and the velocity time integral of flow at the annulus
33 Quantitative pulsed Doppler parameters Supportive signs of severityNeed to add pros/cons of CW, PW and pulm veinCW jet profilePros: simple, readily availableCons: qualitativePW peak mitral E velocityPros simple, readily available, A wave dominance excludes severe MR (severe MR = increased diastolic flow across the mitral valve = increased E velocity)Cons: influenced by LA pressure, LV relaxation, MV area, and atrial fibrillationQuantitative PwCons: measurement of flow at the MV annulus less reliable in calcific MV. Not valid with concomitant significant AR unless pulmonic site is usedPulm veinsPros: simpleCpms: influenced by LA pressure, afib.
35 2D-TEE localization of MR defects Probe inStandard midesophageal positionTee provides a systematic method to accurately localize MR defects and improves preoperative assessmentFoster et al. Ann Thorac Surg 1998;65:1025
36 2D-TEE localization of MR defects Probe at 0 degrees, effects of flexion or withdrawal and retroflexion or advancementFoster et al. Ann Thorac Surg 1998;65:1025
37 2D-TEE localization of MR defects 40 to 90 degrees, effect of clockwise and counterclockise probe rotationFoster et al. Ann Thorac Surg 1998;65:1025
38 3D-TEETo simulate a surgeon’s view of the valve, the 3D TEE image is positioned with the aortic valve the 11-o’clock position.
39 Intra-Operative 2D and 3D TEE Depiction of MV Prolapse and Leaflet Flail Schematic (upper row) and 2D as well as 3D echocardiographic examples of a patient with a normal mitral valve (left panels), mitralvalve prolapse (P1, middle panels) and a flail mitral valve (P2, right panels) as visualized with 2D TEE (long-axis mid esophageal TEEviews (middle row) and real-time 3D TEE volume rendering from the left atrial perspective (bottom row). The surgical views obtainedwith real-time 3D TEE provide unique visualization and better understanding of the anatomic relationships of the mitral valve annulus,commissures and leaflets. Abbreviations as in Figures 1 and 2.
41 3D-TEE quantitative analysis of the mitral apparatus Examples of 3D renderings of the mitral valve obtained from 3D-TEE dataset using software designed for quantitative analysis of themitral apparatus. (Top, Left) Antero-posterior diameter is shown in green. (Top, Right) Annular height. (Bottom Left) Anterior mitral leafletsurface area (hatched) with posterior middle scallop leaflet prolapse. (Bottom, Right) Angle between the mitral and aortic annuli. Aanterior, P posterior, AL anterolateral, PM posteromedial, Ao aorta, TEE transesophageal echocardiography.
42 CMR Etiology of mitral regurgitation Quantitation of mitral regurgitationBetter determination of volumes and LVEF (facilitatingsurgical decision making in asymptomatic patients)
43 LVOT stackA) Left ventricular outflow tract (LVOT) stack prescription is created by obtaining parallel slices across the mitral valve perpendicular to the long axis of the valve.
44 LVOT Borderline-severe MR Eccentric anteriorly-directed flow jet MVP of P2 scallop with flail posterior leafletMildly enlarged LV with NL systolic functionLVEF was normal at 68%Effective forward LVEF moderately at 35%LV Stroke volume 145 mlMitral Valve regurgitant volume 70 mlNormal RV cavity size and systolic functionRVEF normal at 53%Mild RAE. Mild-to-moderate LAE.
46 TherapyThe distinction between primary and secondary MR is keyCorrection of primary MR in a timely fashion reverses LV remodeling, PHTN, and heart failureIt is less obvious that correcting secondary MRwill be curative or beneficial
47 Primary MRNo conclusive data showing that medical therapy (vasodilators or beta-blockers) is effective in primary MR without heart failure (however recommended for heart failure)Surgical therapy- Mitral valve repair instead of replacement is the preferred method in non-rheumatic valves
50 Secondary MR Should be treated with standard heart failure therapy In selected patients, CRT reduces amount of MRNo evidence of improved survival with annuloplastyAlso divergence of opinion about whether MR should be corrected during revascularization
52 Limitations of ring annuloplasty AOLALVPapillary MuscleTetheringForcesRing AnnuloplastyIschemicDoesn’t address tetheringFurther ventricular remodeling after ring
53 Percutaneous therapies Alfieri procedureSchematic of edge-to-edge MV repair (Alfieri procedure; (top) and percutaneousmitral annuloplasty (bottom), capitalizing on the relationshipbetween the coronary sinus and the annulus.Percutaneous mitralannuloplasty
54 Noninvasive assessment for percutaneous MVR Role of TEE
55 Take home pointsNeed to use multiple criteria for more accurate assessmentof MRImportance of distinguishing primary from secondary MRIn secondary MR, indications for mitral valve interventionare less certain and more data are needed
56 ReferencesRecommendations for evaluation of the severity of native valvular regurgitationwith 2D and Doppler echocardiography. J Am Soc Echocardiogr 2003;16O’Gara et al. The role of imaging in chronic degenerative mitral regurgitation.JACC Cardiovascular Imaging 2008;1Carabello. The current therapy for mitral regurgitation. JACC 2008;52