诊断学 13.Electrocardiography(五年制2013-12讲课幻灯)配套课件学习资料

Electrocardiography

(ECG)Dr.Shen-JiangHuTheFirstAffiliatedHospitalCollegeofMedicineZhejiangUniversityBasicKnowledgeECGwaveformsandintervalsBasicECGWaveformsandIntervalsWavesofQRSComplexBasicKnowledgeElectrocardiographicLeadSystemThreeBipolarLeadsinSixExtremityLeads

LeadI：leftarm（+）rightarm（-）

LeadII：leftleg（+）rightleg（-）

Lead

III：leftleg（+）leftarm（-）LeadsconnectionChestLeadsElectricalAxisHowtocalculateQRSmeanaxisLeadI:+15mmLeadIII:(+8mm)+(-2mm)=6mmTheQRSmeanAxisNormalrightleftaxisdeviationaxisdeviationMeasurementandNormalECGMeasurementandNormalECGPWaveinNormalECGPwaveduration：＜0.12s(120ms)Pwaveamplitude：＜0.25mV（limb），＜0.20mV（chest）PRinterval：0.12-0.20sQRSComplexinNormalECGQRScomplexduration：＜0.11s(0.06-0.10s)QRSComplexinNormalECGQRSpatterninleadsV1,V2：rS，noq；

r＜1.0mV，r/S＜1；QRSpatterninleadsV5,V6：qR、qRs、Rs、R；R＜2.5mV,R/s＞1;QRSComplexinNormalECGQRSpatterninlimbleads：R(I,II),S(aVR)andr(aVR)＜0.5mV;QRSamplitudeinlimbleads：R(I)＜1.5mV,R(aVL)＜1.2mV,R(aVF)＜2.0mVQRSComplexinNormalECGQRSamplitude：limbs:QRS＞0.5mV,chest:QRS＞0.8mV；Q:＜0.03s,＜1/4RSTSegment,TandUWave

inNormalECGSTsegment:①ST↓＜0.05mV;②ST↑0.2mV(V2,V3);ST↑＜0.1mV(V4～V6,limbleads)Twave:amplitude：＞1/10RQ-Tinterval:0.32-0.44s;QTc=QT/√RR:

≤0.45s(M),0.46s(F)

AtrialEnlargementand

VentricularHypertrophy

RightAtrialEnlargementPwaveinleadV1orV2≥

1.5mmPwaveinleadII,III,andaVF≥2.5mmPwaveispeaked(P"pulmonale")DurationofPwaveisnormalLeftAtrialEnlargementLeadIIDurationofPwave≥

0.12sec.Pwavebecomebifid(P"mitrale")Thedistanceoftwopeak≥

0.04sec.LeadV1Pwavebecomebiphasicterminalnegativewave＞1mmdeepand＞40mswide,Ptfv1

≥︱0.04︱mm·secLeftVentricularHypertrophyA.IncreasedvoltageRv5orRv6>2.5mV;RV5+SV1>3.5mV(female),4.0mV(male);

RI>1.5mV;

RaVL>1.2mV;

RaVF>2.0mV;RI+SIII>2.5mV;B.Leftaxisdeviation

C.STdepressionandTinversioninV5-6.RightVentricularHypertrophyA.Increasedvoltage(adultsover30)R/SratioinV1>1.0;R/SratioinV5orV6≤1.0;R/qorR/SratioinaVR

≥1;RV1+SV5>1.05mV(severe>1.2mV);RaVR>0.5mV;B.Rightaxisdeviation≥+900(severe>+1100).C.STdepressionandTinversionV1-2.BiventricularHypertrophyA.

NormalECG.B.

Oneventricularhypertrophy.C.

BiventricularHypertrophy.

MyocardialInfarctionMyocardialInfarction

(1)Basicchanges“Hyperacute”TWavesorTwaveinversion.STElevations

PathologicQWavesTWaveChanges(MyocardialIschemia)STSegmentChanges(MyocardialInjury)TheAbnormalQwaveandQSComplex(MyocardialInfarction)ECGChangesinMyocardialInfarctionMyocardialInfarction

(1)Basicchanges“Hyperacute”TWavesorTwaveinversion.TallpeakedTwaves,oftenappearastheearliestECGsignofacuteMI,thenTwavedownward.

STElevations.TheSTsegmentelevatedintwoormoreleadsandmaybestraightenedandfusewiththeTwave(mono-phasiccurve)

PathologicQWaves.thesuddendevelopedQwavemayindicateanacuteMI.(2)ProgressiveECGchangesProgressiveECGchanges

(3)LocalizationofMyocardialInfarction

LeadswithAbnormalQWavesinMILeadswithAbnormalQWavesLocationofMIV1

V3AnteroseptalV3

V5AnteriorI,aVL,V5

V6LateralV1

V5ExtensiveAnteriorII,III,aVFInferior

V7

V9

posterior

V3R

V4RrightventricleLocalizationofLimbLeads

(3)LocalizationofMyocardialInfarction

LeadswithAbnormalQWavesinMILeadswithAbnormalQWavesLocationofMIV1

V3AnteroseptalV3

V5AnteriorI,aVL,V5

V6LateralV1

V5ExtensiveAnteriorII,III,aVFInferior

V7

V9

posterior

V3R

V4RrightventricleLocalizationof

ChestLeads

(3)LocalizationofMyocardialInfarction

LeadswithAbnormalQWavesinMILeadswithAbnormalQWavesLocationofMIV1

V3AnteroseptalV3

V5AnteriorI,aVL,V5

V6LateralV1

V5ExtensiveAnteriorII,III,aV