内科护理学课件 英语 考试资料dysrhythmias

Dysrhythmia

心律失常Propertiesofcardiactissue心脏组织的特性Automaticity自律性:abilitytoinitiateanimpulsespontaneouslyandcontinuously.Excitability兴奋性:abilitytobeelectricallystimulated.Contractility收缩性:abilitytorespondmechanicallytoanimpulse.Conductivity传导性:abilitytotransmitanimpulsealongamembraneinanorderlymanner.Conductionsystem:abriefreview传导系统PwavebeginswiththefiringoftheSAnodeandrepresentsdepolarization去极化ofthefibersoftheatria心房,resultinginatrialcontraction心房收缩.TheQRScomplexrepresentsdepolarization去极化oftheventricles心室,resultinginventricularcontraction心室收缩.TheTwaverepresentsrepolarization复极oftheventricles心室,orthetimeatwhichtheventriclesreturntotheprestimulatedstate.Conductionsystem:abriefreviewIntervals波间隔betweenthesewavesreflectsthelengthsoftimeittakesfortheimpulsestotravelfromoneareaofthehearttotheother.

ThePRintervalrepresentstheperiodduringwhichtheimpulsespreadsthroughtheatria,AVnode房室结,bundleofHis希氏束,andPurkinje浦肯野纤维.TheQRSintervalrepresentsthetimeittakesfordepolarization去极化ofbothventricles.TheQTintervalrepresentsthetimeittakesforcompletedepolarization除极andrepolarization复极oftheventricles.DysrhythmiaDysrhythmiaisanabnormalcardiacrhythmintermsofthefrequencyoftheimpulse频率,rhythm节律,originsite起源部位,conductionvelocity传导速度andexcitementorder冲动次序.ClassificationofDysrhythmia

心律失常的分类

Abnormalimpulseformation冲动形成异常sinusdysrhythmia窦性心律失常sinustachycardia窦性心动过速sinusbradycardia窦性心动过缓窦性心律不齐sinusarrest窦性停搏ectopicrhythm异位心律Passiveectopicrhythm被动性异位心律Escaped

逸博Escapedrhythm逸博心律Activeectopicrhythm主动性异位心律期前收缩PrematureContractionParoxysmaltachycardia阵发性心动过速atrialflutter房扑，atrialfibrillation房颤ventricularflutter室扑，ventricularfibrillation室颤Abnormalimpulsecomduction冲动传导异常Physiological:生理性：interferenceandseparationofAV干扰和房室别离pathological病理性：blockofSA窦房传导阻滞blockofatrialpathway房内传导阻滞blockofatrioventricularpathway房室传导阻滞Blockofbundlebranch束支或分支阻滞或室内阻滞房室间传导途径异常：WPW预激综合征Sinustachycardia窦性心动过速

Clinicalassociation:

Itassociatedwithphysiologicalstressorssuchasexercise,fever,pain,anxiety,hypotension,hypovolemia低血容量,anemia,hypoxemia低氧血症,hypoglycemia低血糖症

,myocardialischemia,CHF,andthyrotoxicosis甲状腺毒症.Italsocanbeaffectedbydrugssuchasepinephrine,norepinephrine,caffeine,atropine阿托品,theophylline茶硷

,nifedipine硝苯地平

,hydralazine胼酞嗪(降压药)Sinustachycardia窦性心动过速

Significance:Theclinicalsignificanceofsinustachycardiadependsonpatient’stoleranceoftheincreasedHR.Thepatientmayhavesymptomsofdizziness头晕,hypotension低血压mayoccur.AnginaoranincreaseininfarctsizemayaccompanypersistentsinustachycardiainthepatientwithMI心肌堵塞.TreatmentThetreatmentisdeterminedbyunderlyingcauses.Incertainsetting,β-blockertherapyisusedtoreducedHRanddecreasemyocardialoxygenconsumption.SinustachycardiaECGcharacteristicsHRisgreaterthan100bpm,rhythmisregular.ThePwaveisnormal,precedeseachQRScomplex,andhasanormalcontourandfixedinterval.ThePRintervalisnormalandtheQRScomplexhasanormalcontour.Sinusbradycardia窦性心动过缓

Clinicalassociation临床联系:

Itoccursinresponsetohypothermia低体温

,carotidsinusmassage按压颈动脉窦,increasedintraocularpressure眼内压

,increasedvagaltone迷走神经紧张

,andadministrationofparasympathomimetic拟副交感神经药drugs.Diseasesstatesassociatedwithsinusbradycardiaarehypothyroidism

甲状腺机能减退,increasedintracranialpressure颅内压,obstructivejaundice阻塞性黄疸andinferiorwallMI.Sinusbradycardia窦性心动过缓

Significance意义:Theclinicalsignificanceofsinusbradycardiadependsonhowthepatientstoleratesithemodynamically.HypotensionwithdecreasedCOmayoccurinsomecircumstances.Treatment治疗:forthepatientwithsymptoms,administrationofatropine

阿托品

,andanticholinergicdrug抗胆碱能药

.Pacemakertherapymayberequired.Sinusbradycardia窦性心动过缓ECGcharacteristicsHRislessthan60bpm,rhythmisregular.ThePwaveprecedeseachQRScomplex.ThePRintervalisnormalandtheQRScomplexhasanormalcontourandnormallength.PrematureAtrialContraction(PAC)房性期前收缩APACisacontractionoriginatingfromanectopicfocus异位病灶

intheatriuminalocationotherthanthesinusnode.Itoriginatesintheleftorrightatriumandtravelsacrosstheatriabyanabnormalpathway,creatingadistortedPwave.AttheAVnode房室结,itisstopped(nonconductedPAC),delayed(lengthenedPRinterval),orconductednormally.ItmovesthroughtheAVnode,andinmostcases,itisconductednormallythroughtheventricles.PrematureAtrialContraction(PAC)房性期前收缩ClinicalassociationInanormalheart,itcanresultfromstressortheuseofcaffeine,tobaccooralcohol.Italsocanresultfromdiseasesstatessuchasinfection,inflammation,hyperthyroidism甲亢,COPD,heartdiseases,valvulardiseases.APACandalsobecausedbyenlargedatria.Significance:aPACmaybeprelude前奏tosupraventriculartachycardias室上性心动过速.Treatment:dependsonpatient’ssymptoms.Withdrawalofsourcesofstimulationsuchascaffeinemaybewarranted.Drugssuchasdigoxin,quinidine奎尼丁,

,procainamide普鲁卡因,flecainide氟卡尼

,andβ-blockerscanbeused.PrematureAtrialContraction(PAC)房性期前收缩ECGcharacteristicsHRvariesandrhythmisirregular.ThePwavemaybenotched缺迹orhavenegativedeflection逆向的偏转,oritmaybehiddenintheprecedingTwave.QRSisusuallynormal,iftheQRSintervalis0.10secondorlonger,abnormalconductionthroughtheventricleispresent.ThePRintervalmaybeshorterorlongerthannormalPRinterval,butitswithinnormallimit.Paroxysmalsupraventriculartachycardia(PSVT)

阵发性室上性心动过速PAVTisdysrhythmiaoriginatinginanectopicfocusanywhereabovethebifurcationofthebundleofHis希氏束分支.PSVToccurringviaanaccessorypathway旁路途径isdesignatedasorthodromic顺向orantidromic逆向性

tachycardia.Paroxysmalsupraventriculartachycardia(PSVT)

阵发性室上性心动过速Orthodromic顺向referstoanterograde顺时,orforward向前conductionthroughtheAVnodeandretrograde逆行,backward向后conduction,throughtheaccessorypathway.Antidromic逆向referstotheopposite:anterogradeconduction顺时传导throughtheaccessorypath旁路途径

andretrogradeconduction逆行传导throughtheAVnode.Paroxysmalsupraventriculartachycardia(PSVT)

阵发性室上性心动过速ClinicalassociationInthenormalheart,PSVTisassociatedwithoverexertion,emotionalstress,changesofposition,deepinspiration,andstimulationandstimulantssuchascaffeineandtobacco.Inadiseasesstate,PSVTisassociatedwithrheumaticheartdisease,Wolff-Parkinson-White(WPW)预激综合症(conductionviaaccessorypathways),digitailisintoxication,coronaryarterydiseaseorcorpulmonary.Paroxysmalsupraventriculartachycardia(PSVT)

阵发性室上性心动过速Significance:aprolongedepisodeandHRgreaterthan180bpmmayprecipitateadecreasedCOwithhypotensionandmyocardialischemia.Treatment:vagalstimulation迷走神经刺激:carotidmassage按摩颈动脉窦ortheValsalvameneuverValsalva动作pharmacologictherapy:adenosine腺苷

,verapamil异搏定

,diltiazem地尔硫卓

,digitalis洋地黄andpropranolol心得安

.However,dititalis洋地黄andcalciumchannelblockerscancausehemodynamiccollapse

inWPWsyndrome.Paroxysmalsupraventriculartachycardia(PSVT)

阵发性室上性心动过速ECGcharacteristicsHRis150to250bpmandrhythmisregular.ThePwaveisoftenhiddenintheprecedingTwaveandhasanabnormalcontour.ThePRintervalmaybeprolonged,shortenedornormalQRScomplexmayhaveanormalorabnormalcontour.Atrialflutter心房扑动Atrialflutterisidentifiedbyrecurring,regular,sawtooth-shapeflutterwaves锯齿形扑波.Atrialflutterisrelativelyraredysrhythmia.Clinicalassociation:Itrarelyoccursinanormalheart.Indiseasestates,itisassociatedwithCAD,hypertension,mitralvalvedisorders,pulmonaryembolus肺栓塞,corpulmoale肺心病,cardiomyopathy心肌病,hyperthyroidism甲亢

andtheuseofdrugssuchasdigitalis,quinidine奎尼丁

,andepinephrine.Atrialflutter心房扑动Significance:highventricularratesassociatedwithatrialfluttercandecreaseCOandcauseseriousconsequencesuchasheartfailure,especiallyinthepatientwithunderlyingheartdisease.Treatment:Electricalcardioversion心脏电复律maybeusedtoconverttheatrialfluttertosinusrhythminanemergencysituation.Drugsusedincludeverapamil异搏定,digoxin洋地黄

quinidine奎尼丁

,procainamide普鲁卡因

andβ-blockers.Atrialflutter心房扑动ECGcharacteristicsAtrialrateis250to330bpm.

Theventricularratevariesaccordingottheconductionratio.In2:1conduction,theventricularrateistypicallyfoundtobeapporximately150bpm.Atrialrhythmisregular,andventricularrhythmisusuallyregular.ThePwaveisrepresentedbysawtoothwaves锯齿波orFwaves.ThePRintervalisavailable.QRScomplexisnormalincontour.Atrialfibrillation心房颤抖Atrialfibrillationischaracterizedbyatotaldisorganizationofatrialelectricalactivity电生理活动withouteffectiveatrialcontraction心房收缩.Ventricularresponse心室反响isirregular,andifthepatientisuntreated,theventricularratewillbe100to160bpm.Thedysrhythmiamaybechronicorintermitten.Clinicalassociation:itusuallyoccursinthepatientwithunderlyingheartdisease;italsoassociatedwiththyrotoxicosis甲状腺毒症,alcoholism,infection,gastroenteritisandstress.Atrialfibrillation心房颤抖Significance:ItoftenresultinadecreaseinCOduetoineffectiveatrialcontractionsandarapidventricularresponse.Thrombi血栓mayformintheatriaasaresultofineffectiveatrialsystemmayoccurasacomplicationwithsubsequentdevelopmentofastroke.TreatmentInemergenysituation,cardioversion心脏电复律maybeusedtoconvertatrialfibrillationtonormalsinusrhythm.Medicationusedincludedigoxin洋地黄,

verapamil异搏定,quinidine奎尼丁

,procainamide普鲁卡diltiazem地尔硫卓,andβ-blockers,flecainide氟卡尼

,propafenone普罗帕酮

andsotalol施太可盐酸索他洛尔

.Atrialfibrillation心房颤抖ECGcharacteristicsAtrialratemaybeashighas350to600bpm.Theventricularratevariesfromaslowas50toashighas180bpm.Atrialrhythmischaotic混乱,andventricularrhythmisirregular.ThePwaveshowsfibrillatorywaves房颤波(fwave),butnodefinitePwavescanbeobserved.ThePRintervalisnotmeasurable.QRScomplexusuallyhasanormalcontour.Prematureventricularcontractions

室性期前收缩Prematureventricularcontractions:isacontractionoriginatinginaectopicfocus异位节律intheventricles.TheQRSwaveisusuallywiderthan0.12seconds.TheTwaveisgenerallylargeandoppositeindirectiontothemajordeflectionoftheQRScomplexPrematureventricularcontractions(PVC)室性期前收缩PVCareinitiatedfromdifferentfoci病灶appeardifferentincontour不同轮廓fromeachotherandarecallmultifocalPVCs多灶性期前收缩.WheneveryotherbeatisPVC,itiscalledventricularbigeminy心室二联律.WheneverythirdbeatisPVC,itiscalledventriculartrigeminy心室三联律.Prematureventricularcontractions(PVC)室性期前收缩TwoconsecutivePVCsarecalledcouplets成对室性期前收缩.ThreeconsecutivePVCsarecalledtriplets.Ventriculartachycardia室性心动过速occurswhentherearethreeormoreconsecutivePVCs.WhenaPVCfallsontheTwaveofprecedingbeat,theRonTphenomenonR波落在T波上现象occursandisconsideredtobedangerousbecauseitmayprecipitateventriculartachycardia室性心动过速orventricularfibrillation心室颤抖.Prematureventricularcontractions(PVC)室性期前收缩Clinicalassociation:

Isassociatedwithstimulationsuchascaffeine,alcohol,aminophyline氨茶碱,epinephrineanddigoxin.Theyarealsoassociatedwithhypokelemia低钾血症,hypoxia缺氧,fever,exercise,andemotionalstress.DiseasestatesassociatedwithPVCincludesMI,CHFandCAD.Significance:

Inheartdiseases,dependingonfrequency,PVCsmayreducetheCOandprecipitateanginaandheartfailure..Treatment:

FortreatingPVCs,

lidocaine利多卡因isthedrugofchoice.Procainamide普鲁卡因

istheseconddrugofchoiceiflidocaineisineffective.Prematureventricularcontractions(PVC)室性期前收缩ECGcharacteristicsHRvaries.Rhythmisirregularbecauseofprematurebeat.Aretrograde逆行Pwaveispossible,andPwaveisrarelyvisiblebecauseisusuallylostintheQRScomplexofPVC.ThePRintervalisnotmeasurable.QRScomplexiswideanddistortedinshape,morethan0.01second.Ventriculartachycardia室性心动过速TheECGdiagnosisofventriculartachycardiaismadewhenarunofthreeormorePVCsoccurs.TheQRSisdistorted歪曲inappearancewithadurationexceeding0.12secondandwiththeST-TdirectionpointingtothemajorQRSdeflection..Ventriculartachycardiamaybesustained持续性(lastinglongerthan30seconds)ornonsustained非持续性(lasting30secondsorless).VentriculartachycardiaClinicalassociation:IsassociatedwithacuteMI,CAD,significantelectrolyteimbalances,cardiomyopathy心肌病,longQTsyndromeandcoronaryreperfusionafterthrombolytictherapy溶栓治疗后冠状动脉再灌注.Isalsocanbeobservedinthepatientwhohasnotheartdiseases.Significance:Theappearanceofventriculartachycardiaisanominous不祥sign.ItmaycauseaseveredecreasedinCO.Theresultmaybepulmonaryedema肺水肿,shock休克,andinsufficientbloodflowtothebrain大脑血流量缺乏.Ventricularfibrillation心室颤抖maydevelop..VentriculartachycardiaTreatment:

Ifthepatientishemodynamicallystable,treatmentconsistsofadministrationoflidocaine利多卡因bolus,Procainamide普鲁卡因

istheseconddrugofchoiceiflidocaineisineffective.Ifthepatientisunconsciousorhemodynamicallyunstable,immediatecardioversion心脏电复律istherecommendedtreatment.VentriculartachycardiaECGcharacteristicsVentricularrateis110to250bmp.Rhythmmayberegularorirregular.ThePwavemaybedissociatedfrom脱离QRScomplex,oritmaybeburiedinQRScomplexesorTwaves.ThePRintervalisnotmeasurable.QRScomplexisprolongedformorethan0.10secondsandtheQRScomplexisdistorted.Ventricularfibrillation心室颤抖VentricularfibrillationisaseverederangementoftheheartrhythmcharacterizedontheECGbyirregularundulations波动ofvaryingcontourandamplitude.Thisrepresentsthefiringofmultipleectopicfoci异位病灶intheventricle.Mechanicallytheventricleissimply“quivering颤抖〞,andnoeffectivecontractionorCOoccurs.Ventricularfibrillation心室颤抖Clinicalassociation:

ItoccursinacuteMIandmyocardialischemiaandinchronicdiseasessuchasCADandcardiomyopathy心肌病.Itmayoccurduringcardiacpacing心脏起搏orcardiaccatheterizationprocedures心导管检查asaresultofcatheterstimulationoftheventricle.Itmayalsooccurwithcoronaryreperfusion冠状动脉重新灌注afterthrombolytictherapy溶栓治疗.Otherclinicalassociationsareaccidentalelectricalshock,hyperkalemia高钾血症andhypoxemia低氧血症.Ventricularfibrillation心室颤抖Significance:

Itresultsinunconsciousness昏迷,absenceofpulse,apnea呼吸困难,andseizure癫痫.Ifleftuntreated,thepatientwiththisconditionwilldie.Treatment:

Immediateinitiationofcardiopulmonaryresuscitation心肺复苏(CPR)andinitiationofadvancedcardiaclifesupport(ACLS)measures高级心脏生命支持withuseofdefibrillationanddefinitivedrugtherapy.Ventricularfibrillation心室颤抖ECGcharacteristicsHRisnotmeasurable.Rhythmirregularandchaotic.ThePisnotvisible.ThePRintervalandtheQRSintervalarenotmeasurable.FirstdegreeAVblockI度房室传导阻滞FirstdegreeAVblockisatypeofAVblockinwhicheveryimpulseinconductedtotheventriclesbutthedurationofAVconductionisprolonged.ThisismanifestedbyPRintervalgreaterthan0.20second.AftertheimpulsemovesthroughtheAVnode,itisusuallyconductednormallythroughtheventricle.FirstdegreeAVblockI度房室传导阻滞Clinicalassociation:itisassociatedwithMI,chronicischemiaheartdiseases,rheumaticfever风湿热,hyperthyroidism甲亢,vagalsimulationanddrugssuchasdigitalis,β-blocker,flecainide氟卡尼,andIVverapamil异搏定.Significance:firstdegreeAVblockmaybeaprecursorofhighdegreesofAVblock.Treatment:thereisnotreatmentforthefirstdegreeAVblock.FirstdegreeAVblockI度房室传导阻滞ECGcharacteristicsAtrialrateisnormal,andrhythmisregular.ThePwaveisnormal.ThePRintervalisprolongedformorethan0.20second.QRScomplexusuallyhasanormalcontour.SeconddegreeAVblock,TypeI

I型二度房室传导阻滞TypeIAVblockincludesagraduallengtheningofthePRinterval,andaQRScomplexisdroped.TypeIAVblockmostcommonlyoccursintheAVnode,butitcanalsooccurintheHis-PurkinjeSystem.Clinicalassociation:typeIAVblockmayresultfromuseofdrugssuchasdigoxinorβ-blocker.ItmayalsobeassociatedwithischemiacardiacdiseaseandotherdiseasesthatcanslowAVconduction.SeconddegreeAVblock,TypeI

I型二度房室传导阻滞Significance:

isusuallyaresultofmyocardialischemiainaninferiorMI.Itisalmosttransientandisusuallywelltolerated,however,itmaybeawarningsignal预警信号ofimpendingsignificantAVconductiondisturbance.Treatment:

ifthepatientissymptomatic,atropine阿托品isusedtoincreasedHRoratemporarypacemaker临时起搏器maybeneeded,especiallyifthepatienthasanacuteMI.SeconddegreeAVblock,TypeI

I型II度房室传导阻滞ECGcharacteristicsAtrialrateisnormal,andventricularratemaybeslowerasaresultofdroppedQRScomplexs.Ventricularrhythmisirregular.ThePwavehasanormalcontour.ThePRintervalisprogressivelylengthensbeforethenonconductedPwaveoccursPR间期逐步延长，直至下一个P波受阻不能下传至心室，andaQRScomplexisdropped.QRScomplexhasanormalcontour.SeconddegreeAVblock,TypeII

II型二度房室传导阻滞TypeIIAVblock:APwaveisnonconducted,andthisalmostalwaysoccurswhenabundlebranchblockispresent束支传导阻滞.TypeII AVblockalmostalwaysoccursintheHis-Purkinjesystem浦肯野系统.Second-degreeblockisamoreseroustypeofblockinwhichacertainnumberofimpulsefromthesinusnodearenotconductedtotheventricles.Thisoccursinratiosof2:1or3:1,andsoonthentherearetwoPwavestooneQRScomplex,threePwavestooneQRScomplex.SeconddegreeAVblock,TypeII

II型二度房室传导阻滞Clinicalassociation:TypeIIAVblockisassociatedwithrheumatic风湿性andatherosclerotic粥样硬化性heartdisease,acuteanteriorMI,digitalistoxicity.Significance:

ItoftenprogressestothirddegreeAVblockandisassociatedwithapoorprognosis.Itisanindicationfortherapywithapermanentpacemaker.ThereducedHRmayresultindecreasedCOwithsubsequenthypotensionandmyocardialischemia.SeconddegreeAVblock,TypeII

II型二度房室传导阻滞Treatment:

Temporarytreatmentbeforeinsertionofapermanentpacemakerinvolvestheuseofatemporarypacemaker.Drugssuchasatropine阿托品,epinephrineordopamine多巴胺canbetiredastemporarymeasurestoincreaseHRuntilpacemakertherapyisavailable.SeconddegreeAVblock,TypeII

II型二度房室传导阻滞ECGcharacteristicsAtrialrateisnormal,andventricularratedependsontheintrinsicrateandthedegreeofAVblock.Sinusrhythmisregular,butventricularrhythmmayirregular.ThePwavehasanormalcontour.ThePRintervalmaybenormalorprolongedbutremainsfixedonconductedbeats.QRScomplexwidensmorethan0.12secondbecauseofbundlebranchblock.Third-degreeAVblock

三度房室传导阻滞Third-degreeAVblock:iscompleteheartblock,constitutesoneformofAVdissociation房室别离inwhichnoimpulsefromtheatriaareconductedtotheventricles.Theatriaarestimulatedandcontractindependentlyoftheventricles.Theventriclerhythmisanescaperhythm,andfocusmaybeaboveorbelowthebifurationoftheHisbundle希氏束.Third-degreeAVblock

III度房室传导阻滞Clinicalassociation:isassociatedwithfibrosis纤维化

orcalcification钙化

ofthecardiacconductionsystem,CAD,myocarditis,cardiomyopathy心肌炎,openheartsurgeryandsomesystemicdiseasessuchasamyloidosis淀粉样变性andscleroderma硬皮.Significance:italmostalwaysresultindecreasedCOwithsubsequentischemiaandheartfailure.

.Treatment:

TemporarypacemakermaybeinsertedoranexternalpacemakerappliedonanemergencybasisinapatientwithacuteMI.Drugssuchasatropine,epinephrineordopaminecanbetiredastemporarymeasurestoincreaseHRandsupportBPbeforepacemakerinsertion.Third-degreeAVblock

III度房室传导阻滞ECGcharacteristicsAtrialrateisusuallyasinusrateof60to100bmp.Theventricularratedependsonthesiteofblock.Atrialandventricularrhythmareregular,butasynchronous.ThePwavehasanormalcontour.ThePRintervalisavailableandthereisnotimerelationshipbetweenthePwaveandtheQRScomplex.QRScomplexisnormalifescaperhythmisinitiatedinthebundleofHisorabove.ItiswidensifescaperhythmisinitiatedbelowthebundleofHis.Clinicalmanifestationofdysrhythmia

Possibleassessmentfinding:IrregularHRandrhythm,palpationsChest,neck,shoulderorarmpainDizziness,syncopeDyspneaExtremerestlessnessDecreasedlevelofconsciousnessFeelingofimpendingdoomNumbness,tinglingofarmsWeaknessandfatigueCold,clammyskinDiaphoresisPallorNauseaandvomitingEmergencymanagementdysrhythmia

Establishandmaintainairway.Anticipateneedforintubationifrespiratorydistressevident.Administeroxygenvianasalcannula.EstablishIVlinewithlarge-gaugeneedle.A