心电专业知识讲座

RightAtriumPulmonaryArteryVenacavaAortaPulmonarycapillaryRightVentricleLeftatriumLeftventriclePulmonaryveinSystemiccapillaryThecardiovascularsystemconsistsoftheheartandbloodvessels心电专业知识讲座第1页心电专业知识讲座第2页心电专业知识讲座第3页

TissuefluidcirculationBlood

circulationLymphcirculation

(Power)Cerebralfluidcirculation心电专业知识讲座第4页人体淋巴系统心电专业知识讲座第5页人体脑室系统心电专业知识讲座第6页人体脑脊液循环心电专业知识讲座第7页

Thevalvesensureone-wayflowofthebloodinthecardiovascularsystemAVvalvesArterialvalves

VenousvalvesLymphaticvalvesBicuspidvalve(Mitralvalve)TricuspidvalveAortasemilunarvalvePulmonarysemilunarvalve心电专业知识讲座第8页ThefunctionofcirculatorysystemTransportsmaterialsthroughoutthebody

Nutrients,water,gases(O2,CO2),hormones,etcKeepshomeostasisofinternalenvironmentRegulatesbodytemperatureEndocrines

atrialdiureticpeptide,vascularactivesubstances心电专业知识讲座第9页CardiacPhysiologyExcitation&conduction（Electricalactivity）Pumpingfunction(mechanicactivity）心电专业知识讲座第10页Chapter9

CardiacElectrophysiology心电专业知识讲座第11页

TheimportanceofcardiacEP1.Basisofcardiaccontractionandpumpingactivity

2.Targetofdrugs3.Arrhythmia:diagnosis,treatment4.Research心电专业知识讲座第12页Section1

Theelectricalactivityof

thecardiomyocyte心电专业知识讲座第13页Transmembranepotential

ofthecardiomyocyteRestingpotential:varieswithdifferentcellsMaximaldiastolicpotential:shownonlyincellswithautorhythmicity心电专业知识讲座第14页TypesofthecardiomyocytesFastresponsecells:

1.Contractile(working)cells:ventricularmyocytesatrialmyocytes2.Autorhythmiccells:Hisbundle,PurkinjefibersInternodalpathwaysSlowresponsecells:1.Autorhythmiccells:

pacemakercellsinsinusnode,atrial-nodalzoneandnodal-HiszoneoftheAVnode2.Non-autorhythmiccells:cellsinAVnodalzone心电专业知识讲座第15页心电专业知识讲座第16页心电专业知识讲座第17页心电专业知识讲座第18页心电专业知识讲座第19页atrial-nodalzonenodalzonenodal-HiszoneHisbundleinternodalpathwaysAVnodeThestructureofAVnode心电专业知识讲座第20页心电专业知识讲座第21页心电专业知识讲座第22页心房肌希氏束浦氏纤维心室肌窦房结房室结心电专业知识讲座第23页心电专业知识讲座第24页1.Transmembranepotentialofthe

cardiacworking(contractile)cellsRestingpotential:

80

90mV,IK1channel(Kirchannel)Actionpotential:fastresponse,4phases心电专业知识讲座第25页APofatrialmyocyteAPofventricularmyocyte心电专业知识讲座第26页心电专业知识讲座第27页IonicbasisoftheAPofcardiaccontractilecellsPhase0(depolarizingphase):

INaPhase1(fastrepolarizingphase1):

ItoPhase2(plateauphase):IK,ICalPhase3(fastrepolarizingphase2)

:

IK,IK1Phase4(restingpotential):

IK1,Na+pump,etc心电专业知识讲座第28页心电专业知识讲座第29页心电专业知识讲座第30页心电专业知识讲座第31页心电专业知识讲座第32页Figure9-6ICalinventricularcell

Figure9-7IKrandIKsindogventricularcellIKrIKs心电专业知识讲座第33页心电专业知识讲座第34页心电专业知识讲座第35页2.DiastolicdepolarizationincardiacautorhythmiccellsPurkinjefiber:If,IK

Pcellinthesinusnode:If,ICaT,IKr

心电专业知识讲座第36页IonicbasisoftheAPofPurkinjefibersPhases0-3:similarwithcontractilecellPhase4(diastolicdepolarization):

If,IKDifferentnamesofIf:Ih

(hyperpolarizationactivatedcationchannel)PacemakercurrentIonicbasisofIf:Na+K+心电专业知识讲座第37页心电专业知识讲座第38页IonicbasisofthepacemakercellinsinusnodePhases0:ICalPhase3:IKPhase4:If,ICaT心电专业知识讲座第39页ArightwardshiftofthecurvemeansagreaterIfatthesamemembranepotential心电专业知识讲座第40页EarlyafterdepolarizationDelayedafterdepolarization心电专业知识讲座第41页Section2

Theelectricalcharacteristics

ofthecardiomyocyte心电专业知识讲座第42页PhysiologicalcharacteristicsofcardiomyocyteExcitability（兴奋性）Conductivity（传导性）Autothythmicity(orpacemakeractivity)（自律性）Contractility（收缩性）心电专业知识讲座第43页ExcitabilityFactorsthatdeterminethe

excitability:Na+(orCa2+)channelproperties:

restingactivationinactivation

excitableexcitatednon-excitableARP,ERP(2)Thedistancebetweenrestingpotential(maximaldiastolicpotential)andthresholdpotential心电专业知识讲座第44页心电专业知识讲座第45页PeriodicchangesoftheexcitabilityofLVcardiomyocyteafterexcitation

absoluterefractoryperiod(ARP)(0-55mV)effectiverefractoryperiod(ERP)(0-60mV)relativerefractoryperiod(RRP)(60-80mV)supranormalperiod(SNP)(80-90mV)Normalexcitability(90mV)心电专业知识讲座第46页心电专业知识讲座第47页Postrepolarizationrefractoriness

1.Normal:slowresponsecell,therecoveryofICalisslow,suchthatthemembraneisstillrefractoryafterfullrepolarization.2.Abnormal:myocardialinfarction/reperfusion心电专业知识讲座第48页PVCCompensatorypause心电专业知识讲座第49页Factorsthataffecttheexcitability

Ions:

[K+]o:slighthigh[K+]oincreasesexcitabiltyserioushigh[K+]odecreasesexcitabilty

low[K+]oincreasesexcitabilty[Ca2+]o:high[Ca2+]oslightlydecreasesexcitabiltyviaaffectingNa+channel

low[Ca2+]oincreasesexcitabiltypH:lowextracellularpH(acidosis)心电专业知识讲座第50页2.Autorhythmicity(自动节律性）Sinusnodeisthedominantpacemakeroftheheart

Sinusrhythm（窦性节律）Latentpacemaker(潜在起搏点）Ectopicpacemaker（异位起搏点）Waysbywhichsinusnodecontrolstheheart:Capture(抢先占领）Overdrivesuppression(超速驱动抑制）心电专业知识讲座第51页Factorsthataffecttheautorhythmicity:

VelocityofdiastolicdepolarizationMaximaldiastolicpotentialThresholdpotential心电专业知识讲座第52页Autonomicnervecontroloftheautorhythmicity:

SympatheticdischargeincreasestheautorhythmicityVagalnervedischargedecreasestheautorhythmicity心电专业知识讲座第53页Keypoint

Question:WhycardiocytehasaverylongAPD?Answer:Toguaranteethattheheartdoesnottetanize(强直收缩，痉挛）,butexcitesandcontractsperiodically.心电专业知识讲座第54页3.Conductivity(传导性）Themyocardiumisafunctionalsyncytium(机能合胞体）,theexcitationcanconductdirectlybetweencardiaccells.心电专业知识讲座第55页心电专业知识讲座第56页心电专业知识讲座第57页Conductionpathways

1.TheconductionofexcitationintheatriumPreferentialpathway(inter-atrialpathway)Inter-atrialcontractilecellconduction心电专业知识讲座第58页心电专业知识讲座第59页A-Vblock1stdegree:A-VconductionslowingP-Rintervalprolongation

1:1conduction2nddegree:(1)PRintervalgradualprolongation,thenaQRSlost(2)2:1conduction,PRintervalmaynotnecessarilyprolong3rddegree:completeAVblock,AVdissociation

心电专业知识讲座第60页2.Theconductionofexcitationintheventricle心电专业知识讲座第61页Howtomeasurecardiacconduction?心电专业知识讲座第62页1.Electricalmapping(标测技术）

Multi-electrodearray2.Opticalmapping

Voltage-sensitivedye心电专业知识讲座第63页ApexRVLVLADSockElectrodeArray(125bipolarelectrodes)2D3D心电专业知识讲座第64页RVLVApexEarlysiteIsochronalmap(GlobalEpicardium)ApexRVLVLADSockelectrodearrayGlobalepicardialmappingofVT心电专业知识讲座第65页3.2cm3.8cmPlagueElectrodeArray(480bipolarelectrodes)心电专业知识讲座第66页Dogheart心电专业知识讲座第67页ComputerizedElectricalMappingshowingthepropagationofcardiacactivationB(3882)C(3902)E(3942)A(3867)D(3917)F(fiberorientation)SeptumRVRVLV心电专业知识讲座第68页G(1342)A(1252)H(1432)B(1272)D(1297)E(1307)C(1292)I(fiberorientation)SeptumRVLVF(1322)Conductionblock,wavebreak,andtheinitiationofVFduringrapidpacing心电专业知识讲座第69页CardiacWedgePreparation心电专业知识讲座第70页MappingareaEpiEarlysiteOpticalMap

(TransmuralSection)

EndoOpticalmappingoftheoriginofventricularautomaticity心电专业知识讲座第71页a.0msb.3msc.8msd.11msPMendo1cmepie.21msf.51msg.71msh.91msxy300msxy心电专业知识讲座第72页Section3

SurfaceECG心电专业知识讲座第73页NormalhumanSurfaceECG心电专业知识讲座第74页心电专业知识讲座第75页Pwave:

Atrial(leftandright)activation

Amplitude:<0.25mV;Duration:0.08-0.11secP-Rinterval:

Atrialactivationtime+A-VconductiontimeDuration:0.12-0.20secQRScomplex:ventriculardepolarizationS-Tsegment:

alltheventricularcellsareactivated.upwardshift:downwardshift:Twave:ventricularrepolarizationTawave(atrialTwave):atrialrepolarizationmergedinQRSQ-Tinterval:ventricularactivationtime(depol+repol)Uwave:mechanismandsignificanceunkown心电专业知识讲座第76页HowsurfaceECGforms?心电专业知识讲座第77页ECGleadsBipolarlimbleads(Standardleads):measurethepotentialdifferencebetweentwopoints.

LeadI:leftarm(+)——rightarm(－)

LeadII:leftleg(+)——rightarm(－)

LeadIII:leftleg(+)——leftarm(－)心电专业知识讲座第78页IfthethreelimbsofEinthoven‘striangle(assumedtobeequilateral)arebrokenapart,collapsed,andsuperimposedovertheheart,thenthepositiveelectrodeforleadIissaidtobeatzerodegreesrelativetotheheart(alongthehorizontalaxis)(seefigurebelow).

Similarly,thepositiveelectrodeforleadIIwillbe+60ºrelativetotheheart,andthepositiveelectrodeforleadIIIwillbe+120ºrelativetotheheart.

Thisnewconstructionoftheelectricalaxisiscalledtheaxialreferencesystem.

Withthissystem,awaveofdepolarizationtravelingat+60ºproducesthegreatestpositivedeflectioninleadII.

Awaveofdepolarizationoriented+90ºrelativetotheheartproducesequallypositivedeflectionsinbothleadIIandIII.

Inthislatterexample,leadIshowsnonetdeflectionbecausethewaveofdepolarizationisheadingperpendiculartothe0º,orleadI,axis.“爱氏三角”心电专业知识讲座第79页(2)Unipolarlimbleads

Thecombinationoftheelectrodesofleftarm,rightarmandleftlegshowroughlyazeropotential,thispointiscalled

centralreferencepoint(中心电端）Unipolarlimbleads(单极肢体导联）：measurethetruepotentialofapointonthebodysurface,

include:

VR,VL,VF（Nomoreused）AugmentedLimbLeads(Unipolar)(加压单极肢体导联）:3resistancesareloaded,thecentralreferencepointis“really”zero.

aVR,aVL,aVF心电专业知识讲座第80页Theaxialreferencesystem

TheaVLleadisat-30ºrelativetotheleadIaxis;aVRisat-150ºandaVFisat+90º.

ThesixlimbleadsoftheECGrecordelectricalactivityalongthefrontalplane(冠状面)

relativetotheheart.

Usingtheaxialreferencesystemandthesesixleads,itissimpletodefinethedirectionofanelectricalvectoratanygiveninstantintime.

Ifawaveofdepolarizationisspreadingfromright-to-leftalongthe0ºaxis,thenleadIwillshowthegreatestpositiveamplitude.

Ifawaveofdepolarizationismovingfromleft-to-rightat+150º,thenaVLwillshowthegreatestnegativedeflection,etc.心电专业知识讲座第81页(3)Chestleads(Unipolar):V1-V6Thesearesixpositiveelectrodesplacedonthesurfaceofthechestovertheheartinordertorecordelectricalactivityinaplaneperpendiculartothefrontalplane(figure).

Awaveofdepolarizationtravelingtowardaparticularelectrodeonthechestsurfacewillelicitapositivedeflection.

心电专业知识讲座第82页Cellpolarizesatrestingcondition,nopotentialdifferenceexitsbetweendifferentsitesCellisdepolarizing(activating),justlikeelectricdipole(电偶极子）movement.source

sink

Duringcelldepolarizing,Electrodeatthenegativesiderecordsadownwarddeflection,andanupwarddeflection,viceversa.MembranepolarizationhypothesisofECGinterpretation（ECG形成膜极化学说）Duringcellrepolarizing,Thesourceisbehindthesink,theelectrodesrecorddeflectionsinoppositedirectionsvsdepolarization.心电专业知识讲座第83页

Thebodyactsasaconductoroftheelectricalcurrentsgeneratedbytheheart,itispossibletoplaceelectrodesonthebodysurfaceandmeasurecardiacpotentials.

Byconvention,awaveofdepolarizationheadingtowardthepositiveelectrodeisrecordedasapositivevoltage(upwarddeflectionintherecording).

VolumeConductorPrinciplesofECGInterpretation（ECG形成容积导体原理）CardiactissueatrestingstateCardiactissuepartiallyexcited心电专业知识讲座第84页心电专业知识讲座第85页

Whatisvolumeconductor?Ifyouputacell(电池）intothecenterofacontainerfilledwithsaltsolution,thesolutionwillbechargedandbecomeavolumeconductor.Thenearerapointawayfromthepositivepole,thehigherthepotentialis.Thepotentialatagivenpointcanbecalculatedbytheequation:

V=E(cos/r2)(V,voltage.E,electromotiveforce)ABr

V心电专业知识讲座第86页

Similarly,thebodyisavolumeconductor,theheartislikeanElectricdipole(电偶极子)duringactivation.itispossibletoplaceelectrodesonthebodysurfaceandmeasurecardiacpotentials.心电专业知识讲座第87页Vector(矢量，向量）isaphysicalvariancewhichshowsbothquantity(intensityorlength)anddirection,forexample,themechanicalforce,electricalcurrent,etc.Theparallelquadranglelawoftheresultant

(协力平行四边形法则）Vectorcardiogram(向量心电图，心电向量图）depictschangesincurrentvectorlengthanddirectionatdifferenttimesduringthecardiaccycle.心电专业知识讲座第88页SequenceofventriculardepolarizationandQRScomplex心电专业知识讲座第89页Sequenceofmyocardialactivationandvectorring心电专业知识讲座第90页Keypoint:TheECGrecordedbyeachofthesixlimbleadsistheprojectionofthefrontalvectorringontherespectiveleadaxis.(六个肢体导联所统计心电图是额面向量环在各导联上投影)心电专业知识讲座第91页Vectorrings:

1.Pvectorring2.QRSvectorring3.TvectorringNormalQRSandTvectorringsQRSandTvectorringsincardiachypertrophy心电专业知识讲座第92页心电专业知识讲座第93页心电专业知识讲座第94页心电专业知识讲座第95页Whatwillhappenifheartrateistoofast?1.Decreaseincardiacoutput

2.Instabilityofcardiacelectrophysiology,VF3.Heartfailure心电专业知识讲座第96页EpicardiogramHR333bpmVFHR200bpmPeriodicHR300bpmAlternance心电专业知识讲座第97页PacingInterval(ms)CL-PI(ms)300250220200190180(VF)PacingInterval(ms)301297303300207172205176VFAB500msPerioddoublingbifercationandchaosduringrapidpacing心电专业知识讲座第98页Perioddoublingbifurcationandchaos心电专业知识讲座第99页Period-doublingbifurcationtochaosduringrapidpacing室颤PacingInterval（ms）△CycleLength(ms)心电专业知识讲座第100页CycleNumberPCL300msPCL190msPCL170msPCL160ms,VF规则模式（正常）ABAB模式（交替）ABCDABCD模式浑沌（chaos）CL(ms)心率加紧时出现激动周期倍增和VF诱发心电专业知识讲座第101页室速向室颤转化时倍周期分岔和浑沌现象规则心跳(心率200BPM)2.交替节律(ABAB模式）(心率300BPM)3.ABCDABCD模式(心率316BPM)4.浑沌(chaos),室颤激动周期(心率333BPM)心电专业知识讲座第102页024681012141618160180200220240A024681012141618240250260240220210D024681012141618160200180220260140240024681012141618120140160