医学诊断学课件：Electrocardiography

Electrocardiography

(ECG)BasicKnowledgeECGwaveformsandintervalsMeasurementandNormalECG0.04

sec0.2

sec10mm/mVPWaveinNormalECGPwaveduration：＜0.12s(120ms)Pwaveamplitude：＜0.25mV（limb），＜0.20mV（chest）PRinterval：0.12-0.20sQRSComplexinNormalECGQRScomplexduration：＜0.11s(0.06-0.10s)WavesofQRSComplexQRSComplexinNormalECGQRSpatterninleadsV1,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；QWave:＜0.04s,＜1/4R0.04

sec0.2

secSTSegmentinNormalECGSTsegment:

①ST↓＜0.05mV

②ST↑＜0.2mV(V2,V3);ST

↑＜0.1mV(V4～V6,limbleads)TWaveinNormalECGTWave:

①TWavedirectioninlinewith

the

main

wave

ofQRS:

I,II,V4～V6↑;aVR↓②TWaveamplitude:≥1/10RWaveinthesameLeads

AtrialEnlargement

RightAtrialEnlargementPwaveinleadV1orV2

≥

1.5mm

(0.15mV)PwaveinleadII,III,andaVF

≥2.5mm(0.25mV)Pwaveispeaked(P"pulmonale")DurationofPwaveisnormalLeftAtrialEnlargementLeadIIDurationofPwave≥

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

0.04

sec.LeadV1Pwavebecomebiphasicterminalnegativewave＞1mmdeepand＞40mswide,Ptfv1≥︱0.04︱mm·secLeadIILeadV1

VentricularHypertrophy

LeftVentricularHypertrophyA.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.ElectricalAxisTheQRSmeanAxis

deviationand

VentricularHypertrophy

NormalrightVentricularHypertrophyleftVentricularHypertrophyBiventricularHypertrophyA.

NormalECG.B.

Oneventricularhypertrophy.C.

BiventricularHypertrophy.

MyocardialIschemiaandInfarction单个心肌细胞除极、复极方向与探测电极方位的关系探测电极cardiacmyocytes

depolarizationandrepolarizationTWaveChanges(MyocardialIschemia)STSegmentChanges(MyocardialInjury)TheAbnormalQwaveandQSComplex(MyocardialInfarction)ECGChangesinMyocardialInfarctionMyocardialIschemia

STElevation:ST

↑>

0.1mV;(V2,V3)ST↑>

0.2mV(M),>

0.15mV(FM);STdepression:ST↓>0.1mV;(V2,V3)ST↓>0.05mVTwaveinversion:T↓>0.1mVinR/S

>1LeadsStableanginapectoris无胸痛时静息时胸痛（痉挛）胸痛缓解后Variantanginapectoris(coronaryarteryspasm)MyocardialInfarction

“Hyperacute”TWavesorTwaveinversion

TallpeakedTwaves,oftenappearastheearliestECGsignofacuteMI,thenTwavedownward.

STElevationsTheSTsegmentelevatedintwoormoreleadsandmaybestraightenedandfusewiththeTwave(mono-phasiccurve)PathologicQWavesThesuddendevelopedQwavemayindicateanacuteMI.ProgressiveECGchanges

LocalizationofMyocardialInfarction

LeadswithAbnormalQWavesinMILeadswithAbnormalQWavesLocationofMIV1

V3AnteroseptalV3

V5AnteriorI,aVL,V5

V6LateralV1

V5ExtensiveAnteriorII,III,aVFInferior

V7

V9

posterior

V3R

V4RrightventricleLocalizationofLimbLeadsLocalizationof

ChestLe