內(nèi)科-Myocarditis心肌炎-課件

1Myocarditis2DefinitionMyocarditisisdefinedclinicallyasinflammation

oftheheartmuscle.Theinflamationmaynotonlyinvolvethemyocytes,but

slsoinvolvetheinterstitium,vascularelements,and/orpericardium.Epidemiology

Truecasesofviralmyocarditisarelikelymorecommonthancurrentlydiagnosed,largelybecauseofitsproteanmanifestationsandrelianceonmyocardialbiopsiesforpathologicalconfirmation.Epidemiologythepreciseincidenceofmyocarditisisdifficulttoascertain.Oneestimate:about8to10per100,000,However,becauseoffailuretomaketheappropriatediagnosisorfailuretodetectsubclinicalcases,manydeathscausedbymyocarditismaygounrecognized.theprevalenceofmyocarditisamongunselectedautopsyseriesisashighas1to5per100.

Whenpatientswithonlyidiopathicdilatedcardiomyopathyareconsidered,myocarditisaccountsfor10to40percentofthecasesoverall.Thissuggeststhatclinicalmyocarditisisnotclinicallysuspectedinalargenumberofcases,leadingtodeathsorsevereheartfailure.5EpidemiologySex:Incidenceissimilarbetweenmalesandfemales.Age:myocarditiscanbepresentinanyage,butpatientsusuallyarefairlyyoung.Etiology

Theinflamationofthemyocardiumcausedbyspecificpathogen,includingvirus,bacteria,fungi,drugorchemical,etal.Themostcommoncausestodayareinfectiousagentssuchasvirusesorparasitesorautoimmuneconditions,especiallybyvirus7EtiologyInfectionViralBacterial,rickettsial,spirochetalProtozoal,MetazoalFungalToxicanthracyclines,cocaineHypersensitivity

Clozapine,

Sulfonamides,Cephalosporins,Penicillins,

TricyclicantidepressantsAutoimmuneActivation

Viralmyocarditis

病毒性心肌炎是指嗜心肌病毒感染引起的，以心肌非特異性間質(zhì)炎癥為主要病變的心肌炎。

Viralmyocarditis(VMC)ispresumedtobeduetoeitheranacutevirusinfectionorapostviralautoimmuneresponse.

EtiologyThemostcommonetiologicalagentforviralmyocarditishastraditionallybeentheenteroviruses,includetheCoxsackievirusandechoviruses10ViralInfectionCoxsackie(A,B)HumanimmunodeficiencyEchovirusesInfluenza(A,B)PolioHerpessimplexVaricella-zosterEpstein-BarrCytomegalovirusRubellaRubeolaVacciniaCoronavirusRabisHepatitisBArbovirusJuninvirusMumpsPathologyThepathogenesisofmyocarditisisaclassicparadigmofcardiacinjury,followedbyimmunologicalresponsefromthehostascardiacinflammation:

1)Evidenceof

myocytenecrosis;2)thepresenceofinflammatorycellsinfiltrate

.

Myocardialinvolvementmaybefocalordiffuse;ThepathologicalchangeisnotspecificfortheetiologicdiagnosisMechanismsVirusinfection心肌組織中直接分離出病毒；在心肌組織上找到特異性病毒抗原。

2)Postviralautoimmuneresponse

臨床上在病毒感染后，經(jīng)過一段潛伏期才出現(xiàn)心臟受累的征象，符合變態(tài)反應(yīng)性疾患的規(guī)律；患者血中可測到抗心肌的抗體；部分患者表現(xiàn)為慢性心肌炎，符合自身免疫反應(yīng)；尸檢中常可在心肌內(nèi)發(fā)現(xiàn)免疫球蛋白（IgG）及補體（β1C）的沉淀Currentunderstandingofthepathogenesisofviralmyocarditisisderivedmostlyfromenteroviralmodelsofmyocarditisinthemouse,andtheprincipleshavebeengeneralizedtoothertypesofmyocarditis.Thediseaserepresentsadelicateinteractionbetweenthevirusandthehost.

Myocarditiscanbeconsideredtohavethreephasesinitspathophysiology.Thefirstistheviralphase,followedbyimmunologicalresponsephase(includinginnateandacquiredimmunitycomponents),followedbycardiacremodelingphase.

ClinicalmanifestationTheclinicalexpressionofmyocarditisrangefromtheasymptomaticstatesecondarytofocalinflammationtofulminantfatalcongestiveheartfailureduetodiffusemyocarditis.Clinicalmanifestation

病毒性心肌炎包括局灶性或彌漫性,病情輕重和感染病毒的量及個體差異有關(guān),感染后臨床表現(xiàn)和預(yù)后不盡相同。Clinicalmanifestation

Acutemyocarditis;Fulminant

myocarditis;

Chronicactivemyocarditis.Clinicalmanifestation

--AcuteMyocarditis

Classically,patientswithmyocarditispresentwithnonspecificsymptomsrelatedtotheheart

themostcommonsymptomsincludefatigue,dyspneaonexertion,arrhythmias(supraventricularandventricular),palpitationsandchestpainatrestAcuteMyocarditischestpainatrestcanbedifficulttodistinguishfromacuteischemicsyndromesbecausetheyresultinreleaseoftroponin,STsegmentelevationonECG,andsegmentalwallmotionabnormalitiesonechocardiogram.Therefore,thesymptomscanbequitenonspecific,althoughsomesymptomsindicatecardiacinvolvement.Viralprodromeoffever,chills,myalgias,constitutionalsymptoms,canbereadilymissedbythepatient,andthuscannotberelieduponfordiagnosis.Clinicalmanifestation

--Fulminant

MyocarditisLessfrequently,thepatientmaypresentwithdramaticacuteheartfailurewithcardiogenicshockintheabsenceofotheretiologies.Thepatientisusuallytoxicinappearance,accompaniedbylowbloodpressureandcardiacoutput,oftenrequireshigh-dosevasopressorsupportorevenaventricularassistdevice--Fulminant

MyocarditisThepatientshaveonechocardiographycharacteristicallysevereglobalventriculardysfunctionbutminimallydilatedleftventricles.Pathologyonendomyocardialbiopsyshowsmultiplefociofinflammationandnecrosisbutdoesnotmatchtheclinicalphenotypicseverity.Muchofthisislikelyrelatedtohighlevelsofcytokineproductionbythehost,leadingtosignificantreversiblecardiacdepression.Clinicalmanifestation

--ChronicActiveMyocarditis

Thisgrouprepresentsthevastmajorityofolderadultpatientswithmyocarditis,andtheonsetisofteninsidiousanddifficulttopinpoint.Thepatientpresentswithsymptomscompatiblewithmoderateventriculardysfunctionsuchasfatigueanddyspnea.Myocardialbiopsypathologymayshowactivemyocarditis,butmorefrequentlyitisonlyborderlineorgeneralizedchronicmyopathicchangeswithfibrosisandmyocytedrop-out.Somemayprogresstodiastolicdysfunctionwithexcessivefibrosis,thusresemblingrestrictivecardiomyopathy.DiagnosisMyocarditishasbeenmoreoftenadiagnosisofexclusion,ratherthanaspecificdiagnosis.Diagnosis1)Medicalhistoryandphysicalsign2)Electrocardiographicabnormalities3)Serummarkersofcardiacdamage4)TheetiologicalevidenceofviralinfectionDiagnosis(一)MedicalhistoryandphysicalsignAhistoryofrecent(1-3weeks)upperrespiratoryinfectionorenteritisNonspecificsymptoms:fatigue,fever,dyspnea,palpitations,chestpain,precordialdiscomfortDiagnosis(一)Medicalhistoryandphysicalsign

tachycardia(outofproportiontothetemprerature),S1isoftenmuffled,Aprotodiastolicgallop,Theheartisdilated,Clinicalevidenceofcongestiveheartfailure,Adams–StokessyndromeDiagnosis(二)ElectrocardiographicabnormalitiesSinus

tachycardia(outofproportiontothetemprerature),SupraventricularandventriculararrhythmiasConductiondelayCompleteheartblockcausingStokes-Adamsattacks,butrarelyrequireapermanentpacerDiffuseST-TwavechangesMyocardialinfarctionpattern(Qwave)Diagnosis(三)referenceindexofcardiacdamage1.Elevatedcardiacenzymes(creatinaseorcardiactroponins),indicatorforcardiacmyonecrosis.

Cardiactroponin(troponinIorT)89%specificityand34%sensitivityandincreasesmorefrequentlythancreatinaseMBsubunits(elevatedinonly5.7%ofpatientswithbiopsy-provend

myocarditis).Diagnosis(三)referenceindexofcardiacdamage:2.EchocardiographySomedegreeofLVdysfunctioniscommonwithsegmentalwallmotionabnormalitiesLVsizeistypicallynormalormildlydilatedWallthicknessmaybeincreasedVentricularthrombidetectedin15%AbnormaldiastolicfillingdespitenormalsystolicfunctionDiagnosis(四)Theetiologicalevidenceofvirus1.Identificationofvirusinstool,throat

washing,blood,myocardium,orpericardialflood2.Adistinct(fourfold)increaseinvirus-neutralizingantibody,or

hemagglutinationinhibitiontitersThedefinitivediagnosisofmyocarditisusuallycanbemadeonlybyendomyocardialbiopsy.30Rightventricularendomyocardialbiopsy(EMB)Criterionstandardfordiagnosisofmyocarditis,althoughitstillhaslimitedsensitivityandspecificity,asinflammationcanbediffuseorfocal.Myocarditisisdescribedas"aninflammatoryinfiltrateofthemyocardiumwithnecrosisand/ordegenerationofadjacentmyocytes"

(Dallasclassification,1987).Diagnosis

1.clinicaldiagnosis:have2criterionsof(一),(二)

and(三)2.identificationofetiologicaldiagnosis:theevidenceofviralinfection3.suspecteddiagnosisforetiology:

Adistinct(fourfold)increaseinvirus-neutralizingantibody,or

hemagglutinatininhibitiontitersDiagnosisSeveremyocarditiscongestiveheartfailure,cardiacshock,

adams-stokessyndromeDiagnosisAcutemyocarditisshouldbesuspectedwheneverapatient,especiallyayoungmale,presentswithotherwiseunexplainedcardiacabnormalitiesofnewonset,suchastachycardia(outofproportiontothetemprerature),arrhythmias,heartfailure,orconductiondisturbances.34DiagnosisCongenital,valvular,ischemic,andpulmonaryheartdiseaseshouldberuledoutWhenitcomestothepresumptivediagnosisofcardiomyopathy.Shouldbemadeonthebasisoftheclinicalandlaboratorypresentations.Thedefinitivediagnosisofmyocarditiscanbemadeonlybyendomyocardialbiopsy.35DifferentialsdiagnosisOtherheartdiseasegeneratingheartfailure.

Congenital,valvular,ischemic,andpulmonaryheartdiseaseshouldberuledoutWhenitcomestothepresumptivediagnosisofcardiomyopathy.Isolated

arrhythmia.Theactivatedβreceptorfunction.Cardiacneurosis36CardiacangiographyToruleout

coronaryischemiaasacauseofnew-onsetheartfailure,especiallywhenclinicalpresentationmimicsacutemyocardialinfarction.37TreatmentMajorityofpatientshaveaself-limiteddisease.Supportivecareisthefirstlineoftherapy.Bedrest(atleastrestrictedactivity).itisrecommendedthatathletesabstainfromsportsfora6-monthconvalescentperiod,anduntilheartsizeandfuntionhavereturnedtonormal.TreatmentManagementofLVdysfunctionsimilartootherformsofcongestiveheartfailureconsidertemporarypacerforcompleteAVblockIntensiveimmunosuppressivetherapy(eg,corticosteroids,azathioprine,cyclosporine).uncertaineffect.Treatment-Immunosuppression

Becauseinflammatorycellinfiltrateshaveconsistentlybeenfoundonthemyocardialbiopsiesorautopsiesofpatientswhohavemyocarditis,thegeneralbeliefhasbeenthatimmunosuppressionshouldbebeneficialformyocarditis.ascurrentunderstandingofinflammationsuggeststhattheimmuneresponsecanbeasmuchprotectiveasharmfulandthatbroadimmunosuppressiveregimensmayproduceasmuchharmasbenefit.im-munosuppressionshouldnotberoutinelyconsideredforpatientswithmyocarditis.patientswithgiantcellmyocarditis,myocarditiscausedbyautoimmuneorhypersensitivityreactions,orpatientswithseverehemodynamiccompromiseand