二尖瓣病理生理學(xué)課件

Epidemiology2019intheUK:6471firsttimevalvereplacementsofwhich28%MVRNumbersincreasingMitralAnnulus:fibro-muscularskeletonAnchorsbaseofvalveleafletsLeaflets:conntissue+muscle+vessels/nervesAnterior(aortic):larger;1/3ofannulusPosterior(mural):2/3ofannulusAnatomyAnatomyPapillarymuscles:AnterolateralPosteromedialChordaetendinae1st,2nd,3rdorderApprox25majorchordaltrunks>100attachmentstoleafletsNoconsensusontimingofmuscleactivitywithcardiaccycleAnnulardynamicsAnnularsizeIncreasesinlatesystole(maximumindiastole)Contractsinpre-systole(minimuminmidsystole)AnnularshapeMoreeccentricinsystoleAnnularpositionMovesuptowardsLAindiastoleMovesdowntowardsLVapexinsystoleLeafletdynamicsOpeningStartsincenter,movingtoedgesFlappingofedgesatmax.openingClosing (beginsinlatediastole)Bulgingatbase/annularattachmentLeafletascendstowardsLABulging‘rolls’fromannulustoedgeMitralStenosis(MS)Aetiology: RheumaticMale:femaleratiois1:2-3Acquiredearly(<20yo?)Butclinicallymanifest10-40yrslaterDefiniteHxofRFin50-60%Pancarditis: mitralvalveinvolvedin90% mitralvalvealonein40%MitralStenosis(MS)Rheumaticdisease:Leafletthickening,calcification,retractionPeriannularcalcification(restrictedmovement)Commisuralfusion:‘fish-mouthing’Chordalthickening,shortening,fusionPapillarymuscleinflammationAlso: calcific congenital neoplastic thrombotic infective iatrogenicMS:HemodynamicsDiastolicAVpressuregradientLApressuremayriseto15-20mmHgatrestGradientriseswithexerciseSmallervalveareahighergradientInflowobstruction:idurationofLVfillingHencereducedcardiacoutputExacerbatedbyhheartrate(e.g.AF)MS:CardiacadaptationsLVessentiallynormalBut?associateddiseasesaffectingLVLAhypertrophyDisorganizedmusclefibres

abnormalconduction/refractoryperiods atrialfibrillation(30-50%,espolder)MaygiveLAmuralthrombiMS:PulmonarychangesInseverechronicMS:PulmonaryHTLApressure>30mmHg:pulmtransudation

reducedlungcompliancePulmartsystolicpressure>60mmHg

impedesRVemptying rightheartfailureUltimatelyirreversiblepulmvascularchangesMS:NaturalhistoryProgressivelife-longdiseaseLonglatencySymptoms:Lowcardiacoutput:dyspnoea,fatiguePulmonarycongestion/HT(orthopnea,PND) rightheartfailure

hemoptysisAtrialfibrillation/Thromboembolism‘Cardiaccachexia’MS:NaturalhistoryOnsetofsymptomstodisability:10years10yearsurvival:Asymptomatic(NYHAclassI)80%(progression)Symptomatic(NYHAclassIII)20%Causesofdeath:CHF60-70%Systemicembolism20-30%Pulmonaryembolism10%Infection1-5%MS:InvestigationsCXR:LAenlargement,pulmcongestionECG:LAenlargement(notchedPinII,V1)atrialarrhythmias?RVHEcho:valvearea,LA/LVdimensionsDoppler:measurespressuregradientsTOE:bettermitral/LAvisualizationCardiaccatheter:notessentialAssocddisease;LVventriculography&pressuresMS:MedicaltherapyPharmacologicalTxofmildheartfailure,bronchitis,arrhythmias,hemoptysisEndocarditisprophylaxisAnticoagulation:HxofAF/thromboembolismBalloon(oropen)ValvuloplastyMS:IndicationsforsurgerySymptomatic(NYHAclassIII-IV):MVR

hlong-termsurvival10yearsurvival: 0-20%90%(89%at15yrs)

hfunctionalcapacityValvearea<1-1.5cm2 (normal4-6

cm2)SystemicemboliMS:IndicationsforsurgeryClassI-II:controversialRiskofSCDifasymptomatic:negligibleSurvivalnotimprovedbyMVR?roleofvalvotomy(pulmonaryHT,AF)MVRindicatedwhen:Valvearea<1.5cm2 PulmonaryHT(higherrisk)Thromboembolism ?PregnancyplannedSymptomprogression>NYHAclassII+MitralRegurgitation(MR)AetiologymorediversethanMSMyxomatousdegenerationLeadingcauseinWest(30-70%)DefectivefibroelastictissuefloppyvalveMostasymptomaticComplicatedbyannulardilatation,chordalrupture,endocarditisRheumaticdiseasenextmostcommonMR:CarpentierclassificationNormalleafletmotionAnnular/ventriculardilatationLeafletdisease/perforation MR:CarpentierclassificationExcessiveleafletmotion(prolapse)Chordal/papillarymuscleelongationorruptureMR:CarpentierclassificationRestrictedleaflet/chordalmotione.g.fibrosis,calcification,retraction MR:AetiologyMitralAnnulusMyxomatousdegenerationSenilecalcificationFunctionaldilatation(e.g.myocarditis)RingabscessMarfan’sMR:AetiologyMitralleafletsRheumaticdisease,endocarditis

(1-30%)UnknownwhysomedevelopMS,othersMRFibrocalcificleafletthickening(withoutfusion)Chordaeshortened,annulusdilatedalso:congenital,connectivetissuediseaseMR:AetiologyChordaeIschaemiaMyxomatousInfectiveConnectivetissueTraumaIdiopathicMR:AetiologyPapillarymuscle

(10-25%)Dysfunction/ruptureIHD/MI:muscle&annularinjuryfrankrupturerare,usuallyfatalesp.PosteromedialmuscleAlso:abscess,sarcoid/amyloid,myocarditisMalalignmente.g.LVaneurysm,dilatation,myopathyMR:HemodynamicsAcute: JLApressure,pulmoedemaChronic:LA/PVcompliance:ipulmcongestnRegurgitantvolumedependson:MitralorificesizeLV-LApressuregradientHeartrateMedicalTxaimstocontrolabovefactorsesp.decreaseafterloadtoreduceLVdilatationMR:CardiacadaptationsLV:hpreload,iafterloadLVdilated,morespherical,thinnedIncreasedSV(O2consumptionnotmarkedlyh)ButdecompensationcangraduallyoccurLA:hsizeinchronicMRhcomplianceLessthromboembloism,AFthanMSMR:SymptomsAcute:pulmonarycongestion&oedemaChronic:maybeprolongedasymptomaticphaseRiskofendocarditisCongestiveheartfailure&fatigueRightheartfailureMR:InvestigationsCXR:LA/LVenlargementECG:normal;LVH,?AF/arrhythmiasEcho:leafletmorphology&functionChamberdimensions,LVfunctionDopplercolourmappingCardiaccatheter:assesscoronaries,LVMRI:Dx,LVvolumes,regurgitantfractionMR:MedicaltherapyMainstay:Afterloadreduction

iregurgitantvolumeipulmcongestion

iLVvolumeimitralorificebut:ongoingLVvolumeoverload10%classI-IIprogresstoIII-IVperyearClassII-IIIsurvivalonmedicalMx:5yea