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ClinicalElectrocardiographyTeachingCourse苏州大学附属二院心内科邵春来GriffithJoyner38yearsolddiedin1998Vivian•fu28yearsolddiedin2003MarcoPantani35yearsolddiedin2004心电图学基础（一）心电发生的原理basicprinciplesoftheelectromechanics（1）心肌静止时restingmyocardium（复极状态repolarizationstatus）（2）心肌细胞受刺激stimulatedmyocardium（从左到右开始除极depolarizationbeginningfromlefttoright）除极方向（3）除极过程processofdepolarization（depolarizationfromlefttoright）除极方向(-+)1.2.3.4.DeplaorizationSequenceofa“Strip”of5MyocardialCellsDepolarizationprogressingfromlefttoright2.whendepolarizationspreadsawayfromanylead,itproducesanegative(downward)deflectioninthatlead.1.whendepolarizationspreadstowardanylead,itproducesapositive(upward)deflectioninthatlead.3.whendepolarizationspreadsfirstlytowardandthenawayfromanylead,itproducesabiphasicdeflection.1)Vector+–+–+–MagnitudeDirectionfrom0Anarrowrepresentstwophysicalparameters:directionandmagnitude2)resultantvector0同一轴axile的二个心电向量的方向相同者，其幅度argument相加；方向相反者则相减。＋ABC＋ABC•VectorsmaybesummedbyparallelogrammethodtoproduceResultantVector=Translate=SummedResultantVectorTheintegrationcanonlybeperformedwhenthetwovectorsaregeneratedatthesamemoment.（二）心血管传导系统cardiovascularconductionsystem心脏的传导系统由以下几部分组成•窦房结SAnode•结间束internodalatrialpathways•房室结AVnode•希氏束AVbundle•右束支rightbundlebranches•左束支leftbundlebranches•Purkinje纤维网PurkinjesystemSAnodeAVnode两结之间用vector表示1342SAnodeAVnode运用4原则记录心脏的vector传导过程位置不重要12341342不同部位记录电极的电位四、心肌的repolarization和T波Ineachcardiaccycletherearemanyinstantvectorsandifthetipofeachvectorisconnectedtogetheraloopwillbeobtained,whichiscalledasvectorloop,suchasQRSloop.四、心肌的repolarization和T波VariouspatternsoftheECGcanbeobtainedfromthesamevectorloop.Thepatterndependsonthepositionoftheelectrode.PTQRS四、心肌的repolarization和T波Intheheartthevectorloop,infact,isathree-dimensionalvectorloop.四、心肌的repolarization和T波ECG,innature,isdoubleprojectionsofathree-dimensionalvectorloop.四、心肌的repolarization和T波frontalplanefrontalplanetransverseplane四、心肌的repolarization和T波Thethree-dimensionalvectorloopprojectsonasectionofthebodyfirst.Thatisthevectorloopofthissection.Then,thevectorloopofthesectionprojectsonalead.ThatistheECGofthislead.（四）心电图导联leadsoftheECG双极肢体导联bipolarextremityRALALLⅠ－＋Ⅰ＝LA－RA，Ⅱ＝LL－RA，Ⅲ＝LL－LA加压肢体导联augmentedextremityleadsaVRaVLaVF包括aVR、aVL、aVF导联＋＋－－＋－Leadv1:4thintercostalspacejusttotherightofthesternumLeadv2:4thintercostalspacejusttotheleftofthesternumLeadv3:alinemidwaybetweenleadV2andV4Leadv4:themid-clavicularlinein5thintercostalspaceLeadv5:theanterioraxillarylineatthesamelevelasleadV4Leadv6:themidaxillarylineatthesamelevelasleadV4angleofLouisTotallydifferentpatternsofthepotential(ECG)canbeobtainedfromthesamecardiaccycle.Thepotential(ECG)patterndependsonthepositionoftheelectrodes.Now,youknow,theECGisagraphicrecordingoftheelectricalcurrentsproducedbytheheartmuscleduringtheatrialandventriculardepolarizationandrepolarization.Insummary心电图的临床应用ClinicalapplicationoftheECG（一）心电图的测量方法determinationmethodoftheECGStandardizedMethods&Devices•ECGPaper•DevicePaperSpeed•DeviceCalibration•ElectrodePlacementHorizontalAxisVerticalAxisEKGPaperStandardizedMethods&Devices•ECGGraphPaper–Verticalaxis-millivolt•1smallbox=1mm=0.1mV–Horizontalaxis-time•1smallbox=1mm=0.04sec.StandardizedMethods&Devices•PaperSpeed&Calibration–PaperSpeed-25mm/secstandard–CalibrationofVoltageisAutomatic–BothSpeedandvoltagecalibrationcanbechangedonmostdevicesWhatistheheartrate?(300/6)=50bpm–QRSinlead12.Findnet+or_QRSinLeadaVF3.ResultantVector.ThisisMeanElectricalAxisofHeartorCardiacVector.Electricalaxisisabout+60oTransitionalzone(chestleads)Representsthelocationofthelead,havingpositiveandnegativedeflectionsofthesamemagnitude.ClockwisenormalCounterclockwise（二）ComponentsoftheECGComponentsoftheECGComplex•PWave–firstupwarddeflection–representsatrialdepolarization–usually0.10secondsorless–usuallyfollowedbyQRScomplexWhentheatriaareexcited,thisdepolarizingelectricalcurrentcanberecordedbyECG,anditisnamedPwave.ComponentsoftheECGComplex•QRSComplex–Compositionof3Waves•Q,R&S•representsventriculardepolarization•muchvariability–usually0.12secComponentsoftheECGComplex•QWave–firstnegativedeflectionafterPwave–depolarizationofseptum–notalwaysseenComponentsoftheECGComplex•RWave–firstpositivedeflectionfollowingPorQwaves–subsequentpositivedeflectionsareR’,R”,etcComponentsoftheECGComplex•SWave–NegativedeflectionfollowingRwave–subsequentnegativedeflectionsareS’,S”,etc–maybepartofQScomplexComponentsoftheECGComplex•PRInterval–timeimpulsetakestomovethroughatriaandAVnode–frombeginningofPwavetonextdeflectiononbaseline(beginningofQRScomplex)