心电图教学英文版.ppt

房颤的发生机制Duringsinusrhythm,theSAnodeservesastheheart’spacemakerwhiletheAVnodeactsasthegatekeepertotheventriclesIllustrationdepictingmacroreentrantcircuitactivityduringarunofcomplexatrialfibrillationVentricularFlutterVentricularFibrillationVentricularflutterpresentsasasinewaveinappearance,regularlargeoscillationatarateof150to300beats/min.Ventricularfibrillationisrecognizedbythepresenceofirregularundulationsofvaryingcontourandamplitude,anddistinctQRScomplexes,STsegmentsandTwavesareabsent.2.心脏传导异常所致的心律失常

arrhythmiasinvolvingabnormalcardiacconduction（1）房室传导阻滞A-Vblock（2）束支传导阻滞与分束支传导阻滞

bundlebranchblock(BBB)andfasciularblock（3）预激综合征

Wolff-Parkinson-Whitesyndrome,WPWsyndrome（1）房室传导阻滞A-Vblock度房室传导阻滞firstdegreeA-Vblock01I°AVBisprolongationoftheatrio-ventricularconductiontime.prolongedP-Rinterval:longerthan0.20secinadultsand0.22sinoldadults.02Ⅱ度房室传导阻滞seconddegreeA-VblockMobitzTypeI(Wenckebackphenomenon)

(1)TheP-Rintervalbecomeslongerandlonger

(2)TheR-Rintervalgetsshorterandshorter,untilthereisablockedornonconductedventricularbeatwithalongpauseⅡ度房室传导阻滞seconddegreeA-VblockMobitzTypeII:(1)ThefixedP-Rinterval(2)Thereisafixednumericalrelationshipbetweenatrialandventricularimpulses,whichmaybe2:1or3:1or4:101arrhythmiasinvolvingabnormalimpulseformation心脏激动异常所致的心律失常02arrhythmiasinvolvingabnormalcardiacconduction心脏传导异常所致的心律失常（四）心律失常

cardiacarrthythmias1.心脏激动异常所致的心律失常

arrhythmiasinvolvingabnormalimpulseformation（1）窦性心律sinusrhythmia（2）交界性心律atrialventricularjunctionalrhythm（3）过早搏动prematurebeat（4）逸搏与逸搏心律escapeandescaperhythms（5）异位性心动过速ectopictachycardia（6）扑动与颤动flutterandfibrillationsinusrhythmandsinusarrhythmiasSinusrhythmECGofSinusRhythms

ThePwaveisupwardinleadI,II,avF,V4-5anddownwardinleadavR