内科学教学课件：心律失常Cardiac Arrhythmia

心律失常

（CardiacArrhythmia)MechanismofarrhythmiaPropertyofcardiacelctrophysiology兴奋性（Excitability)自律性(automaticity)传导性(Conductivity)

ExcitabilityExcitability

indicatesthatmyocardialcellhaselectricalactivitywhenitisstimulatedElectricalactivityofsinglemyocardialcelliscalledactionpotential(AP)ElectricalactivityofwholeheartmakesECG0-60-90+20Thresholdvoltagemv01234ARPERPRRPSuper-conductiveperiodARP:AbsoluteRefractoryperiod;ERP:EffectiveRefractoryperiod;RRP:RelativeRefractoryperiodConductivityElectricalimpulsecanconductinmyocardialtissuebidirectionallyNormalconductionpathway：sinusnode→intranodebundle

→atrioventriculanodeandintraatrialbundle→Hisbundle→rightandleftbundlebranch(includingleftanterosuperior

andposteroinferior)→Purkinjefiber→myocardiumautomaticityCellsspontaneouslydischarging(spontaneousAP,diastolicdepolarization)Automaticityincreasesfromhightolowasfollows:Physiologicalstatus：SN、AVN、HIS、Purkinjepathological：diseasedmyocardialandconductivetissue,etc.PropertyofnormalrhythmImpulsefromSNHeartrateiswithin60～100/minRegularrhythm，PPinterval＜0.12sPRintervalisbetween0.12～0.20s，QRScomplexduration＜0.10sFrontalaxiswithin-30～110°

ItisconsideredasarrhythmiaifanyitemaboveisnotmatchedMechanismsofarrhythmogenesisEnhancedautomaticity

TriggeredactivityAutomaticcellsdiminishormalfunction,DysfunctionofconductivetissuesReentryMechanismsofarrhythmogenesis(1)Enhancedautomaticity

EndogenousorexogenouscatecholamineincreasingAbnormalityofacid,basic,electrolytebalanceIschemia,hypoxiaMechanicalstretchdrugsDisturbanceofnerveandliquidmodulationMechanismsofarrhythmogenesis(2)TriggeredactivityDepolarizingoscillationsofmembranevoltageinducedbyabnormalinwardNa+current(oneormoreprecedingAP)duringearlierorlaterreporlarization,ie,AfterdepolarizationEarlydepolarizationDelayeddepolarizationMechanismsofarrhythmogenesis(3)Automaticcellsdiminishormalfunction,suchassicksinussyndromeDysfunctionofconductivetissues,suchassinoatrialblock,atrioventricularblockorbundlebranchblockaswellasabnormalpathwayMechanismsofarrhythmogenesis(4)Reentryprerequisiteofreentry

ConductioninconsistencyofanatomyorphysiologySingledirectionalconductionblockingDelayedconductionInitialblockingarearecoversexcitability(reentrycyclelengthgreatthanrefractoryperiodoftheblocking)ClassificationofcardiacarrhythmiasClassifiedonpropertyofelectricalactivityAbnormalityofimpulseandconductionClassifiedonheartrate,rapidorslowRapidorslowarrhythmiasClassifiedonclinicalmanifestation,mildorseverFatalornonfatalHighriskorlowriskClassifiedonoriginofarrhythmiasMethodofdiagnosingarrhythmiaanditsevaluation

Symptom

Causedbyabnormalcontractile：palpitation,discomfort,beatingstop,etc.Inducedbycardiacoutputdecreasing：chestcompressingandpain,dizziness,presyncope,syncope,shortofbreathlessFactorsrelatedtosymptom:medications,diet,emotion,infection,etc.MethodofdiagnosingarrhythmiaanditsevaluationSignChangingofrhythm:sloworfast,regularorirregularIntensityofheartsound：S1muffleorloud，cannonsoundRelationbetweencarotidveinwavepulseandheartrate,andchangingofbloodpressureMethodofdiagnosingarrhythmiaanditsevaluationElectrocardiogramMostvaluable:evaluatingarrhythmiatype,property,prognosis,etc.DynamicElectrocardiogram(Holter)Mostvaluable:assessingarrhythmiatype,numbers,distribution,property,prognosis.Evaluatingclinicalsignificance,effectsoftreatment,etc.MethodofdiagnosingarrhythmiaanditsevaluationEsophaguselectrocardiogramDifferentiatingSVTfromVT，understandingmechanismofSVT.Semi-invasive.MethodofdiagnosingarrhythmiaanditsevaluationElectrophysiologicstudy(EPS)Classicalwayofresearchingarrhytnmias.InvasiveAssessingfunctionofSNSinusnoderecoverytime,SNRTSinoatrialconductiontime,SACTAssessingAVconductionAnalyzingmechanisimoftachyarrhythmiasEvaluatingunknownsyncopeMethodofdiagnosingarrhythmiaanditsevaluationExerciseElectrocardiogramSuitableforsomeofarrhythmias,suchasVTOthers

Averagesignaltechnique，suchaslatepotential(LP),QTdispersion,TwavealterationusedforevaluatingprognosisofventriculararrhythmiaSpecificarrhythmiasRapidarrhythmiasPrematurecontractionAtrial,junctional,ventricularTachyarrhythmiasSinus,atrial,supraventricular,junctional,ventricular,atrialflutterandfibrellationBradyarrhythmiasDiseaseofsinus,AVnodeorbundlebranchSpecificarrhythmiasTwosyndromesPreexcitingsyndromeRelatedwithrapidarrhythmiasSicksinussyndrome(SSS)RelatedwithslowarrhythmiassinusarrhythmiasSicksinussyndromeFeaturesofECG(1)Seriouspersistentbradycardia

(often<50bpm)Brady-tachysyndrone,

recurrentepisodeofbothbradyarrhythmiaandsupraventriculartachycardia(AF,AFL,SVT)underbasisofbradyarrhythmia,thereisoftenlongasystoleafterrapidarrhythmiasstop,whichcancausesyncopeorpresyncopeSicksinussyndromeFeaturesofECG(2)Frequentsinusarrestorexitblock

withslowHRBothofsinoatrialandAVnodearediseased

escapeinterval>2s,orslowandpersistentAF\AFL,orslowescaperhythmSicksinussyndromeEtiologyIntrinsic：sinusnodeitselfisinvolved,e.g.ischemia,regressivedegeneration,infiltrationofothercellsortissuesExtrinsic：highvagaltone,hyperkalemia,antiarrhythmics

mostfrequentetiologyareregressivedegenerationandCHDSicksinussyndromeSymptomsIschemiaofbrain,heart,kidneyAdams-StokessyndromeDiagnosisTypicalECGpatternsSymptomsisrelatedwithECGchangingsHolter,provokingtest,treadmillandfinallyelectrophysiologicalstudyforthesuspected.HolterismostvaluableSinusstandstillFeaturesPPintervalelongatesabruptly,basicallyatsinusbradycardia,whichisnotcommonmultiplesofbasicPPintervalEscapebeatorrhythmiscommonseenSymptomsisdependondurationofstandstillSymptomatictreatment,pacemakerisultimatechoicesinoatrialblockClassificationofECGFirstdegreeSABcan`tbeseenonECGThirddegreeSABcan`tbedifferentiatedfromsinusstandstillSeconddegreeSABisdividedintotwosubtype,i.e.typeIandtypeIIseconddegreeSABSymptomsandtherapyaresameassinusstandstillTypeISeconddegreeSABFeaturesofECGPPintervalprogressivelyshortensuntilnextPwavefailstooccurThelongPPintervalthat<normalregularPPintervalTypeⅡsecondarydegreeSABFeaturesofECGPwaveislostabruptly,followedbylongpauseThedurationofthepausetakestheformof2:1,3:1AVconductionEscapebeatorrhythmcanbeenseenSinustachycardiaClinicalfeaturesVerycommon.Etiologyincludingsympatheticexecitation,excise,avtiveinfection,bloodloss,hypoxia,heartfailure,etc.PalpitationorchestdiscomfortareoftencomplainedEtiologicaltreatmentAtrialarrhythmiasPrematureatrialcontractionFeaturesofECGPrematurePwavefollowedbynearnormalQRScomplexQRScomplexissimilartoitfromsinusnodewithincompletecompensatorypauseSometimes,PRintervalisprolonged,PrematurePwavenotconducttotheventricles,oraberrationinventricle,fullcompensatorypausecanbeseenPrematureatrialcontractionClinicalfeaturesCommonseen,provokedbyvarietyoffactors,e.g.infection,inflammation,ischemia,tobacco,alcoholetc.itismorecommonintheelderlySymptomisrelatedtoprolongedcompensatorypause,increasedcontraction,frequentPACandsensitivityofpatientsOnauscultation,irregularbeating,longerinterval,increasedS1TreatmentaimforetiologyexceptobvioussymptomantiarrhythmicscanbegivenAutomaticatrialtachycardiaFeaturesLesscommon.Mosthaveunderlyingdiseases,HRisaround130bpm,>200bpmlessseenPwaveisnotassameassinusone,PRintervalchangingwithslightlyirregularrhythmAVblockwithdifferentratiocanbeseen“Warm-up”canbeseenatitsinitialattackEtiologicalorsymptomatictreatment,RFalsoplaysarolechaoticatrialtachycardiaFeaturesRare,mosthavingbasicdiseaseHRisbetween100-130bpm,atlesttwokindPwavecanbeseenPRandPPintervalarechanging,Pnotconductingsometimes,isoelectricallinebetweenPPintervalcanbeseen,precursorofatrialfibrillationEtiologicalorsymptomatictreatment，antiarrhythmicswithcautionAtrialflutter(AFL)FeaturesofECGPwavedisappears,substitutedbyregularsaw-likeFwavewithitsratebetween220～350bpmVentricularresponse(AVratio)isusually2:1,sometimes4:1orirregularStimulationofvagusnerveorexercisemaydecreaseorincreaseAVratiowithmultipleUsuallyAFLisduetoreantryaroundtricuspidring,andtendtobecomeAFAtrialflutter(AFL)

ClinicalfeaturesHRisusuallyaround150bpmwhichrepresentsAVratiois2:1，mayhavingunderlyingdiseasesTinyandrapidjugularpulsescanbeseenwithitsratebeyond300bpmSimilarmanifestationtoitinatrialfibrillation(AF)RateorrhythmcontroldependsonclinicalpresentationAtrialfibrillation(AF)FeaturesofECGNoPwave,replacedbyrapid,chaoticandtinyatrialwaveswithitsrateof350～600bpmVentricleresponseisirregularlyduetoAVdelay,irregularrateswithnormalQRScomplex,butindividualQRScomplexmayslightlydifferentEtiologiesofatrialarrhythmiasCardiacDegeneration,ischemic,myocarditis,enhancedloadduetovarietyofheartdiseases,hypertension,postCABG,preexcitingsyndrome,loneAFNoncardiacAlcoholabuse,hyper-orhypothyroidism,alterationofvagalorsympathetictone,COPD,pulmonaryembolism,diabetes,sepsisAtrialfibrillation

ClinicalfeaturesCommonwithagingaswellasthosewithunderlyingdiseasesSymptomaticseveritydependsonHR,AFduration,underlyingheartdiseaseTendtoembolismbecauseofthrombosisinatriaMayhavelongcardiacarrestafterparoxysmalAFstops

AtrialfibrillationClinicalfeaturesWithstethoscope,palpatingarterypulseandwatchingjugularpulse,nearallmostofAFcanbediagnosedwithconfidenceAmphasisngpreventionembolismRateorrhythmcontroldependsonclinicalpresentationAFClassificationbasedonfeaturesofepisode:NewclassificationFirst-detectedepisodeRecurrentparoxysmal(self-terminating,<7d)recurrentpersistent(notself-terminating,>7d)permanentOldclassificationparoxysmal,persistentandpermanentAFJunctionalarrhythmiasJunctionalprematurecontractionFeaturesofECGPrematureretrogradePwave(maynotseen)ThePusuallyinfrontofQRScomplex(mayfollowsQRSone),PR’<0.10s，RP’<0.20sMostofthemwithcompletecompensatorypause,QRScomplexnormalorinaberrationJunctionalprematurecontraction

ClinicalfeaturesRathercommon.MostoccurredwithorganicheartdiseaseSimilarfindingstoatrialoneonauscultationSymptomissimilartothatofatrialonesTreatmentisnotnecessaryunlessobvioussymptomNonparoxysmaljunctionaltachycardiaFeaturesLesscommon.Mosthaveunderlyingdiseases,digitalissideeffectAttackgradually,AVdissociationcommon,QRScomplexusuallynormalHRbetween70-130bpm,hemodynamicsrelativelychanginglessEiologicaltreatment,antiarrhythmicsisnotrecommendedSupraventricularparoxysmal(AVnodalreantrant)tachycardiaFeaturesofECGHRbetween160～250bpm,absoluteregular,QRScomplexnarrowing(exceptionofaberration)Occasionally,retrogradePwaveseenReentry(AVnode,AV)ismajorityofmechanismSupraventricularparoxysmaltachycardia

ClinicalfeaturesMostwithoutorganicheartdisease,commonseenAttackwithsuddeninitiationandtermination,maintainingshortforminutesorlongforhours.PalpationismainstreamofsymptomHypotension,collapseisfarlessthanVTGoodreactiontotreatment,e.g.vagalmaneuvers,antiarrhythmics.RadiofrequaceisbestwayforradicalcurePre-excitationorWolf-Parkinson-white(WPW)syndromeFeaturesofECGPRinterval<0.12sornormal,δwaveinonsetofQRScomplexwhichresultinwidenedQRScomplexfollowedbysecondaryST-TchangePRintervalis<0.12s，butQRScomplexisnormal(shortPRsyndromeorLGL(lown-Ganong-Levinesyndrome))FeaturesofPreexcitationsyndromeP-R<0.12sQRS>=0.12s,δwaveSecondaryST-TchangeSTVoftenseenPreexcitationsyndromeClnicalfeaturesPartofpatientshaveonsetofSVT,AF,AFL,itsmechanismisreentryThereareseveraltypesofpreexcitation,e.g.persist,intermittent,latent,concealedItispredisposedtosuddendeathifrefractoryperiodofaccessorypathwayis<270msTherapyisassameasitinSTV,butdigitalis,varapamil,β-blockerareforbiddeninAFattackVentriculararrhythmiasVentricularprematurecontractionFeaturesofECGPrematureQRScomplexwithnoprecedingrelatedPwaveQRScomplexisbizarreinshapewithfullcompensatorypause(insertoneexception)AVdissociationcanbeseen

Ventricularprematurecontraction

ClinicalfeaturesMostcommon.Seenatorganicheartdiseases,someofitinAMIormyocardiopathycaninducefatalarrhythmiaSimilarfeaturestootherprematurecomplexonauscultation.PalpitationisacommoncomplainTreatmentregimenonbasisofclinicalmanifestationVentricularparoxysmaltachycardiaFeaturesofECGHRbetween150～200bpm，regularrhythmQRScomplexbizarreandwidenAVdissociation,ventricularfusionandcaptureVentricularparoxysmaltachycardiaClinicalfeaturesOftenwithorganicdiseases,inducinghemodynamicsdeteriorationcausingremarkablesymptomsBothsustainedandnon-sustainedVTseeninclinicalItshouldbestoppedassoonaspossible(withantiarrhythmicsorDCcardioversion)Varapamil,adenosine,β-blockerareeffectiveforsomespecificVTTorsadedepointes(TDP)FeaturesCongenital(recurrentsyncope,deafness,longQT,i.elongQTsyndrome)Acquired(drugse.g.quinidine,electrolytedisturbance,highdegreeAVB,etc.),atleast80%isacquiredinclinicalLongQTiscommon,oftenVPCatlatediastoleinducingTDPTDPdisplaysaspeakofQRScomplexreversesalongisoelectricline,causingpatientssyncopeTDP,mostofit,terminatingspontaneouslywithseveralsec.Torsadedepointes(TDP)TreatmentDuringattackIncreasingHR：atropine,pacing,isoproterenolInfusionofmagnesium,potassium,lidocaineusefulonlyinafewpatientsDuringreliefeΒ-blocker,calciumantagonist,antiepilepticdrugsLeftsidecervicothoracicsymppatheticganglionectomyorimplantationofcardioverter-defibrillatorinsomerefractorycasesAcceleratedidoventricularrhythmFeaturesCommoninAMI,myocarditis,digitalisintoxicationHRbetween60～120bpm,regular,QRScomplexbizarreBothonsetandceasingaregradualMildeffectonhemodynamicschangingEtiologicaltreatment,antiarrhythmicswithcautionHeartblockingatrioventricularblock，AVBClassificationAcuteandchronicAVBTheacuteismainlyduetomyocarditis,AMI,electrolyteabnormalityandsomedrugsimpactThechronicismainlycausedbyregressivedegenerativefibrosisorconsequenceoftheacuteone1stdegreeAVBFeaturesofECGPRinterval>0.20sinadultsor>0.18sinchildrenMostofitisin0.21～0.35s2nd°typeⅠAVB(Wenchebachblock)FeaturesofECGProgressivePRintervalprolongationoccurs,resultinginanonconductionPwave(thepause),thedurationofthepauseis<twobasicRRcyclesRRintervalprogressivelyshortensFirstPRintervalafterthepauseisshortest,AVconductionratiosusuallyare3:2or4:32nd°typeⅡAVBFeaturesofECGPRintervalisusuallynormalandnochangePwavedonotconductsuddenlyorperiodically,makingthelongpauseThelongpauseismultiplesofbasiccycles3rddegreeAVBFeaturesofECGAVconductionfailscompletelywithAVdissociationVentricularactivityismaintainedbyanescaperhythmarisingfromsitedistaltoHisbunduleAtrialrate>ventricularrateQRScomplexisbroadifpacesitedistaltoHis,otherwiseitisnearlynormalAdvancedAVBrefertothatonlyafewPwaveconductstotheventricles,gettingitssameclinicalsignificantasitinIII°AVBFeaturesofAVBfirstdegreeAVBSeenatinflammation(myocarditis,AMI),drugs,trauma,fibrosis,increasedvagustone,etc.NosymptomsManifestationofAVB

SeconddegreetypeⅠAVBSeenathighvagaltone,drugsmyocarditis,AMI,etc.Noremarkablehemodynamicschange,mayhavewildsymptomsAfewcasesmayprogressworseintosevereAVBManifestationofAVBSeconddegreetypeIIAVBAlmosthasunderlyingheartdiseasesHRisslowandsometimesunstableThosewhoseblockinglevelisdistaltoHisbundlearepredisposedtoprogressintothirdAVBSymptomsareprominentManifestationofAVBThirddegreeAVBAlmosthasunderlyingheartdiseasesHRisslowandunstableThosewhoseblockinglevelisdistaltoHisbundlearepredisposedtoturnintocardiacasystoleorTDP,whichcouldcauserecurrentsyncopeorAdams-Stokes’syndromeManifestationofAVBThirddegreeAVBOnauscultation,intensityofS1variesduetolossofAVsynchrony,cannonsound(wave),S3，S4canbeheardSyncope,presyncope,chestcompressionheartfailure,etc.areseenfrequently.WithhighriskofsuddendeathManagementofAVBFirstorseconddegreetypeIAVBAimforetiologyandsymptoms,followupAVconductionchangingSeconddegreetypeⅡAVBAimforetiologyandsymptoms,closeinvestigationofclinicalmanifestationPatientswithsymptomaticbradyarrhythmiashouldreceiveapermanentpacemakerManagementofAVBThirddegreeAVBThereisevidencethatpacingcanimproveprognosisinthesepatientnomattersymptomaticorasymptomatic,inacutestage,temporarypacemaker,chronicpermanent

Bundlebranchblock(BBB)RightBBB(complete,incomplete)LeftBBB(complete,incomplete)LeftanteriorfascicularblockRBBBplusLeftanteriorfascicularblockIntraventricularblock(nonspecificintraventricularconductiondefect)LeftposteriorfascicularblockRightbundlebranchblockFeaturesofECGDurationofQRScomplex>0.12sVAT(ventricleactivitytime)atrightprecordialleads>0.07sQRScomplexinleadV1isinpatternofrSR`，inV5withablunt,prolongedandshallowSwave,withsecondaryST-TchangingQRScomplexmeasuredis<0.12sisrecognizedasincompleteRBBBLefttbundlebranchblockFeaturesofECGDurationofQRScomplex>0.12sVAT(ventricleactivitytime)atleftprecordialleads>0.07sQRScomplexinleadV1isinpatternofrS，inV5isahigh,blunt,widenRwave,withsecondaryST-TchangingQRScomplexmeasuredis<0.12sisrecognizedasincompleteLBBBClinicalsignificanceofBBBBBBpersehavenosignificanteffectonhemadynamicsBBBmaynotdeteriorateatlongtermfollow-upinpatientswhohavenounderlyingheartdiseasesNewBBBinAMIormyocarditissignifiesclinicaldeteriorationClinicalsignificanceofBBBMostofbilateralBBBwilldevelopcompleteheartblockNoparticulartreatmentunlessthereisindicationofpacingManagementofarrhythmiasMedicationNonmedicationCatheterbased

Ablation(electric,radiofrequecy,cryoablation,Chemo-ablation,laser)ProgrammedelectricstimulationManagementofarrhythmiasNonmedicationpacemakerForbradycardiaFortachycardiaSurgicaloperationCutoff,excision,Foxoperation,CABG,etc.othersDCcardioversion,stimulationofvagusnerve,transesophagealpacingStrategyEvaluatingriskofarrhythmiasDecidingtoTreatingitornotWhichtherapyshouldbechosenWhatistheendpointoftherapyEvaluationofriskRecognitionofmalignantarrhythmiasVentricularflutterorfibrillationSustainedornonsustainedVTAdvancedorcompleteAVBEvaluationofriskRecognitionofmalignantarrhythmiasAForAFLwithrapidventricleresponse

VPCareMultilocal,polymorphic,couplet,tripletandRonTSevereSSSEvaluationofriskSeriousheartdiseasesAMI、seriousmyocarditis,myocardiopathy,hearfailure,takingdigitalisHemodynamicsunstableBloodpressuredecrease,shock,heartfailureorheartfailuredeteriorationwhenononsetofarrhythmiasEvaluationofriskLifequalityisdecreased,whichiscausedbyarrhythmiasSuggestworseprognosiswhenthearrhythmiaAttitudeofmamagementEmergencyUrgentactivePalliativeEmergencytreatmentFatalarrhythmiasSustainedVT,VFL,VFExtremelyslowandunstablebradycardia,asystolewillhappenatanytimeHemodynamicsdeteriorationorshockVT,rapidAForAFL,extremeand/orbradycardias,etc.UrgentmamagementWithseriousheartdiseases(myocarditis,myocardiopathy)WithacutecoronaryischemiaWithremarkabledepressedcardiacfunctionordecompensateheartfailureOndigitalisAbnormalityofacid,basic,electrolytebalanceActivetreatmentToomuchcomplain,lifequalitydecrease,mayinducecomplication,butrelativelynormalheartSuchasfrequentprematurecontraction,AF,SVTpalliatetreatmentAsymptomaticarrhythmiaswithnormalorrelativelynormalheartPrinciplesofmanagementAimforremovalofprovocativefactorsCorrectionofanoxia,ischemia,disturbanceofelctrolyte,acidandbasicControlofheartfailure,infection,inflammation,diminishingside-effectsofdrugsrelevanttoarrhythmiasPrincipleofmanagementMedicationIVadministrationinemergencyCombinationofantiarrhythmicsinnecessary,inwhicheffectwouldbegood，butpossiblesideeffectsalsoincreaseTypeIaisnotusedwithtypeIb,ifso,sideeffectsmayincreasedramaticallyPrincipleofmanagementNonmedicationDCcardioversion,pacingareusuallyusedinemergencyorurgentPacemaker,RF,surgicaloperationareusedincaseswhohavenoorlittleresponseortolerancetomedicaltreatmentEndpointofmanagementEliminationofmalignantarrhythmiasEliminationofsymptomaticarrhythmiasrelievesymptomsPreventionofrecurrentrrhythmiasClassificationofantiarrhythmicdrugs(Vaughan-Willianms)ClassI:inhibiteroffastsodiumchannelClassIa:inadditionprolongrefractoriness,QTinterval,e.g.quinidine,procainamide,disopyramideClassI