Antiarrhythmia-lecture.pptx
- 文档编号:2714879
- 上传时间:2022-11-08
- 格式:PPTX
- 页数:73
- 大小:2.10MB
Antiarrhythmia-lecture.pptx
《Antiarrhythmia-lecture.pptx》由会员分享,可在线阅读,更多相关《Antiarrhythmia-lecture.pptx(73页珍藏版)》请在冰豆网上搜索。
AntiarrhythmicDrugsBackgroundofCardiacElectrophysiologyMembranepotentialofcardiaccellsFastresponse:
restingpotential,High-80-95mv(Atrialmusclestherateofriseofphase0israpidVentricularmusclespropagationwillberapidPurkinjefiber)Na+influx,rapiddepolarizationSlowresponse:
restingpotential,low-50-70mv(sinus,atrioventri-slowdepolarization,Ca2+influxcular(AV)nodelactionpotentialpropagatesslowlycells,impairedfastResponsecells)Phase0:
depolarizationPhase1,2,3:
repolarizationPhase4:
diastolicvoltagetimecourse03:
actionpotentialdurationAPDK+,Cl-ChannelcurrentsPumpExchangerK+Ca2+Na+Na+Ca2+100msOutside0mVNa+intsideMembrance-85mV01234Fastresponse1.Excitability:
relationshipbetweenthresholdpotentialandrestingpotentiallevel2.Automaticity:
3.Conductivity:
conductiverateisdependentonmembraneresponsivenessMembraneresponsiveness:
relationshipbetweenVmaxofphase0andmembranepotentiallevel4.Effectiverefractoryperiod,ERPThetimebetweenphase0andsufficientrecoveryofsodiumchannelsinphase3topermitapropagatedresponsetoexternalstimulusisthe“refractoryperiod”.二Mechanismsofarrhythmias1.Disturbancesofimpulseformation(冲动形成障碍)ThechangesofnormalautonomicmechanismChangeofpacemakercurrent(cell)ofdiastolicautonomicdepolarizationcancauseautonomicalterationsuchas:
mentalstress(tension)drugtoxicityfeverexcitationformationofabnormalautonomicmechanismnon-autonomiccell:
atrialmusclesventricularmusclesautonomiccellrestingpotential:
-60mvabnormalautonomyrepetitiveimpulsearrhythmias2.triggeredactivity(触发活动)andAfterdepolarization(后除极)AEarlyafterdepolarization(EAD,早后除极)Occurinphase2,3,lowpotassium,Ca2+inwardE.A.issecondarydepolarizationthatoccurbeforerepolarizationiscomplete.secondarydepolarizationcommencesatmembranepotentialsclosetothosepresentduringtheplateauoftheactionpotentialBdelayedafterdepolarization(DAD,迟后除极)Occurinphase4,Ca2+overloadincell,Na+inward.D.A.isasecondarydepolarizationthatoccursearlyindiastole,thatis,afterfullrepolarizationhasbeenachieved.3.Disturbancesofimpulseconduction(冲动传导障碍)AcausingpartialandcompleteblockBreentry-fibrillation心室纤颤andflutter心室扑动tachycardiaextrabeats(extrasystoles)formationunidirectionalblockofcardialtissueofreentrycircuitingtractshorteningtheeffectiverefractoryperiodReentrycircuitestablished1forwardimpulseobstructedandextinguished2decrementalconduction(递减传导)andunidirectionalblock(单向阻滞)ofantegrade(顺行)impulse3retrograde(逆行)impulseconductedacrossdepressedregion4reentrycircuitestablishedArrhythmiamaybemanifestasoneorafewextrabeatsorasasustainedtachycardiaReentry(折返):
circusmovementoneimpulsereentersandexcitesareasoftheheartmorethanonceMechanismofthereentryMechanismofthereentry正常心肌单向传导阻滞折返形成4.Genetics/genemutationLongQ-TSYNDROME,LQTS3mutationgenes:
SCN5A/chromosome3:
codingsodiumchannelinmyocardia;HERG/chromosome7:
codingIkrpotassiumchannel(内向整流钾通道);KVLQT1/chromosome11:
codingIkspotassiumchannel(延迟整流钾通道);5.DisturbancesofPotassiumchannelsClassificationofAntiarrhythmicDrugsAntiarrhythmicagentsaredividedintoFOURclassesAntiarrhythmicagentsaredividedintoFOURclassesAssignmenttotherespectiveclassesismadeontheAssignmenttotherespectiveclassesismadeonthebasisofdrug-inducedalterationsinionchannelbasisofdrug-inducedalterationsinionchannelfunctionandcardiacelectrophysiologicpropertiesfunctionandcardiacelectrophysiologicpropertiesTheclassification,whilehelpful,isnotabsoluteandTheclassification,whilehelpful,isnotabsoluteandoverlappingpropertiesexistamongthemanydrugs.overlappingpropertiesexistamongthemanydrugs.A.AntiarrhythmicdrugscandepressNa+inwardofnon-autonomiccellinphase4ordepressCa2+inwardofautonomiccellinphase4depressautomaticityB.AntiarrhythmicdrugscanaccelerateK+outwardofphase3,increasemaximumdiastolicpotential(morenegative)increasevoltagedifferencebetweenmaximumdiastolicpotentialandthresholdpotentialdepressautomaticityQuestion:
Howabouttheconduction?
Classesofantiarrhythmicagents1.sodiumchannelblockingdrugs.2.blockadeofsympatheticautonomiceffectsintheheart3.prolongationoftheERPandAPD4.calciumchannelblockadeClassificationofAntiarrhythmicDrugsClassIa-CharacteristicsMeddlelevelsodiumchannelblock,weaklevelpotassiumchannelblock,andweaklevelcalciumchannelblockinhighconcentrationSlowtherateofriseofthemembraneactionpotential(Phase0;dV/dt)Slowconductionvelocity(PR;QRS)Prolongrefractoriness(QT)Examples-Quinidine*ProcainamideDisopyramideClassificationIClassificationI:
sodiumchannelblockingdrugsClassificationofAntiarrhythmicDrugsClassIb-CharacteristicsWeaklevelsodiumchannelblock,andpotassiumchannelopenLimitedeffectondV/dtofPhase0Slightslow
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- Antiarrhythmia lecture