典型心电图诊断.

典型心电图诊断心内科：党群正常时，每次心动周期在心电图上都可以出现P波、QRS波群、T波和U波、P-R段、S-T段和T-P段，P-R间期和Q-T间期及J点心电图成份的组成及各波段的测量心电图测量RRsqRsRSrSrSr’qRQRQrQSRrsR’QRS波群的命名平均心电轴估测方法示意图图中箭头示QRS主波方向正常心电图P波：反映左、右心房去极化过程中的电位和时间变化。P-R段：反映兴奋通过房室交界区，因其传导非常缓慢，形成的电位变化也很微弱，一般记录不出来而成等电位线。QRS波群：反映左、右心室去极化过程中的电位和时间变化。S-T段：表示心室去极刚结束后尚处于缓慢复极的一段短暂时间，即代表心室早期复极的电位和时间变化。T波：反映心室晚期复极过程中的电位和时间改变。U波：一般认为是心肌传导纤维的复极所造成，也有人认为是心室的后电位。NormalECG(1)Pwave:atrialdepolarizationlAmplitude0.20mvlDuration0.11seclPositiveinI,II,aVF,V4-V6;NegativeinaVR(2)PRinterval:thetimeforintraatrial,AVnodal,andHis-Purkinjeconduction,Duration:0.12~0.20sec(3)QRScomplex:ventriculardepolarizationlThewidth:0.060.10sec,0.11sec.lFromV1toV6,theRwavesgetsbiggerandbigger,theSwavesgetssmallerandsmaller.lR/SlinV1,butR/SlinV5lRinV5andV62.5mv,RinV11.0mvlRinaVR0.5mv,lRinaVL1.2mvandRinaVF2.0mvlRinI1.5mvlQ0.04secinwidth,1/4Rinthesamelead.正常人胸导联R波和S波振幅变化规律示意图(4)STsegment:itreflectsPhase2oftheactionpotential.lSTelevation0.3mVinV1、V2;0.5inV3,0.10mVinV4V6lSTdepression0.05mVinanyleads(5)Twave:repolarizationofventriclesItisuprightinalltheunipolarleadsexceptaVR,andoccasionallyV1.Twave1/10Rinthesamelead,maybe1.21.5mVintheprecordialleads(6)QTinterval:thedurationofdepolarizationandrepolarizaionofventricles.Thenormalrangeis0.320.44sec.(7)Uwave:thewavefollowingtheTwaveandisusuallyverysmall.Itscauseisnotcompletelyunderstood.ElevatedUwave:lowK+inplasma正常心电图心房、心室肥大AtrialEnlargementandVentricularHypertrophy(1)LeftAtrialEnlargementLeadIIDurationofPwave≥0.12sec.;Pwavebecomebifid(Pmitrale);Thedistanceoftwopeak≥0.04sec.LeadV1Pwavebecomebiphasic;Ptfv1-0.04mm·secRightAtrialEnlargementLeadIIPwaveispeaked(Ppulmonale);AmplitudeofPwave≥0.25mVinlimbleads.BiatrialEnlargementLeadIIPwavedurationandamplitudebothincreased.LeftVentricularHypertrophyA.IncreasedvoltageSV1+RV53.5mV(female),4.0mV(male);Rv5orRv62.5mV;RI1.5mV;RaVL1.2mV;RaVF2.0mV;RI+SIII2.5mV;B.LeftaxisdeviationC.STdepressionandTinversioninV5-6.RightVentricularHypertrophyA.Increasedvoltage(adultsover30)R/SratioinV11.0;R/SratioinV5orV6≤1.0;R/qorR/SratioinaVR≥1;RV1+SV51.05mV(severe1.2mV);RaVR0.5mV;B.Rightaxisdeviation≥+900(severe+1100).C.STdepressionandTinversionV1-2.BiventricularHypertrophyA.NormalECG.B.Oneventricularhypertrophy.C.BiventricularHypertrophy.心肌缺血和心肌梗死MyocardialIschemiaandMyocardialinfarctionECGofmyocardialischemiashowsSTsegmentdepression;STsegmentelevation(coronaryspasm);Inverted,diphasic,lowTwave.Myocardialinfarction(1)Basicchanges“Hyperacute”TWaves.TallpeakedTwaves,oftenappearastheearliestECGsignofacuteMI.STElevations.TheSTsegmentelevatedinoneormoreleadsandmaybestraightenedandfusewiththeTwave(mono-phasiccurve)PathologicQWaves.thesuddendevelopedQwavemayindicateanacuteMI.TWaveChanges.TheelevatedSTsegmentsreturntothebaseline,anddeepsymmetricalTwavesappearintheseleads.Tall,symmetrical,uprightTwaveswillappearinreciprocalleadsatthesametime.(2)ProgressiveECGchanges(3)LocalizationoftheECGpatternsLeadswithAbnormalQWavesinMILeadswithAbnormalQWaveslocationofMIV1V3AnteroseptalV3V5AnteriorI,aVL,V5V6LateralV1V6ExtensiveAnteriorII,III,aVFInferior(4)OldmyocardialinfarctAdefinitivediagnosisofoldmyocardialinfarctdependsonthepresenceofapathologicalQwave急性心肌梗死的图形演变及分期心律失常心脏起搏传导系统窦房结位于右心房上腔静脉入口处，是控制心脏正常活动的起搏点，窦房结的冲动经前、中、后三条结间束传导至房室结，向前延续成房室束（又称希氏束）。房室束先发出左束支后分支，再分出左束支前分支，本身延续成右束支，构成三条系统。左束支后分支细长，分支晚；两侧束支于心内膜下走向心尖分支再分支，细支相互吻合成网，称为浦顷野纤维网深入心室肌。心脏起搏传导系统包括窦房结、结间束、房室结、房室束（希氏束）左右束支及其分支以及浦顷野纤维网。心脏的特殊传导系统SINUSRHYTHMANDSINUSARRHYTHMIAS窦性心律和窦性心律失常正常窦性心律正常窦性心律：ECG诊断①频率60－100bpm②PⅠⅡavF直立，avR倒置③PR间期0.12～0.20SSinusrhythmfeatures:(1)EveryPwaveisfollowingbyaQRScomplex;(2)PwaveisuprightinleadI,II,aVF,V4-V6,inverseinaVR;(3)P-Rinterval≥0.12sec;(4)Normalrateis60-100beats/min窦性心动过缓SinusBradycardia(1)Sinusrhythm(2)Heartrate60bpm(R-RintervalorP-Pinterval1.0sec)窦性心动过缓及不齐窦性心动过速（sinustachycardia)成人窦房结冲动形成的速率超过每分钟100次，称为窦性心动过速，速率常在每分钟101－160次之间。窦性心动过速开始和终止时，其心率逐渐增快和减慢。健康人运动和情绪紧张可引起心动过速。酒、茶、咖啡和药物如异丙肾上腺素和阿托品常引起窦性心动过速。在疾病状态中常见的病因为发热、低血压、缺氧、心功能不全、贫血、甲状腺机能亢进和心肌炎。心电图显示窦性p波，p波速率超过每分钟100次，P-R间期大于0.12秒。治疗主要是针对病因，必要时可应用镇静剂或β-受体阻滞剂。窦性心动过速SinusTachycardia(1)Sinusrhythm,rate100bpmTheR-Rinterval(ortheP-Pinterval)0.60sec.(2)P-RandQ-Tintervalareshorterthanusual(3)S-Tsegmentisslightdepression,Twavesmaybeflattened窦性心动过速窦性停搏窦性停搏：ECG诊断①较正常PP间期显著长的时间内无P波，长PP与短PP无倍数关系。②可有逸搏或逸搏心律。SinusarrestThePwavemissedforashorttime窦房阻滞窦房阻滞：Ⅱ°－Ⅰ型①PP间期进行性缩短，出现一次长的PP间期②长PP间期2倍短PP间期Ⅱ°－Ⅱ型①PP间期固定②长PP间期＝2倍短PP间期病态窦房结综合征（SSS)定义：窦房结病变导致的以过缓性心律失常为基础的临床症候群。病因①窦房结内的病变：感染，淀粉样变，纤维化，钙化。②窦房结缺血。③迷走神经张力增高，抗心律失常药应用。SickSinusSyndrome(SSS)(1)Sinusbradycardia(HR50/min);(2)SinusarrestorSAblock;(3)Tachycardia:Atrialtachycardia,AtrialFlutter,Atrialfibrillation;(4)AVblock.病态窦房结综合征（SSS)症状：心脑等器官供血不足的表现心电图表现①显著的心动过缓（50bpm)②窦性停搏或窦房阻滞③窦房阻滞与房室阻滞并存（双结病变）④慢快综合征⑤交界区逸搏心律一、房性早搏提前出现的P波，形态与窦性心律的P波不同，P-R间期＞0.12秒。qrs波群大多与窦性心律相同。有时稍增宽或呈畸形，伴st段及t波相应改变,称为室内差异性传导，需与室性早搏鉴别，前者qrs波群前可见p‘波，P-R间期＞0.12秒，v1qrs波群多为rsr’。提早畸形p'波之后无qrs波出现，称为房性早搏未下转呈阻滞性房性早搏。房性早搏AtrialPrematureContractions(1)TheprematureP'waved