ECG 导联-文档资料

1、ICUHInstitute of Cardiology Union Hospital1导联的连接 I 右上左上 avR 正极连右上 II 右上左下 avL 正极连左上 III 左上左下 avF 正极连左下 胸导 V1 4肋间胸骨右 V2 4肋间胸骨左 V3 V2-V4中点 V4 5肋间左锁骨中线 V5 腋前线V4水平 V6 腋中线V4水平Einthoven三角与六轴系统ICUHInstitute of Cardiology Union Hospital2Einthoven triangleLead I= LA-RALead II=LF-RALead III=LF-LA Lead I + Lea

2、d III= Lead II the left arm, right arm, and left leg form the apexes of an equilateral triangle, while the heart, an electrical point, is assumed to be the center of the triangle. The sides of the triangle are analogous to the three standard limb leads and called lead axes. Transposing the three sid

3、e of the triangle ( lead I, II, III ) to a common central point of zero potential forms the triaxial reference system of Bayley. ICUHInstitute of Cardiology Union Hospital3ICUHInstitute of Cardiology Union Hospital4The Concept of a LeadLeads I II III+-RARALL+-LALLLALEAD IILEAD ILEAD IIIRemember, the

4、 RLis always the groundICUHInstitute of Cardiology Union Hospital5The horizontal or transverse planeICUHInstitute of Cardiology Union Hospital6hexaxial frontal plane额面六轴系统额面六轴系统horizontal planeICUHInstitute of Cardiology Union Hospital7ICUHInstitute of Cardiology Union Hospital8心室肥厚心室肥厚 The resultan

5、t vector points to the left, positeriorly, and inferiorly. Marked increment of the posterior and leftward forces during ventricular depolarization. Increased forces anteriorly and to the right High-amplitude R wave in left chest leads (V5,V6 ) Deep S wave in right chest leads (V1,V2 )Tall R wave in

6、lead V1Deep S wave in V5, V6 ICUHInstitute of Cardiology Union Hospital9 左室肥大 左室的位置及特点 左后方 厚于右侧 ECG表现 QRS电压增高 胸导：Rv5，v62.5mv Rv5+Sv14.0(男)或3.5mv(女) 肢导：R 1.5mv RaVL1.2mv RaVF2.0mv R + S 2.5mlICUHInstitute of Cardiology Union Hospital10电轴左偏QRS时间延长0.100.11s，但0.12s以R波为主的导联可出现ST-T的改变 QRS电压高，同时有ST-T改变， 称为

7、左室肥大合并劳损ICUHInstitute of Cardiology Union Hospital11ICUHInstitute of Cardiology Union Hospital12 右室肥大特点 1/3左室厚 ECG改变改变 V1导联R/S1，V5 R/S1 或 S波加深， 重者V1为qR型 Rv1+Sv51.05mV，avR R/q或R/S1， R0.5mv 电轴右偏+90 ST-T改变ICUHInstitute of Cardiology Union Hospital13ICUHInstitute of Cardiology Union Hospital14 双侧心室肥大 大致

8、正常心电图 向量相抵 单侧心室肥大 一侧掩盖另侧 双侧心室肥大ICUHInstitute of Cardiology Union Hospital15The ECG of biventricular hypertrophyTall R wave in left chest leads plusRight axis deviation , Tall R wave in V1ICUHInstitute of Cardiology Union Hospital16Outline 4. Ischemia and ST-T changes5. Myocardial infarctionICUHInsti

9、tute of Cardiology Union Hospital174. Myocardial ischemia, and ST-T changes心肌缺血与心肌缺血与ST-T改变改变ICUHInstitute of Cardiology Union Hospital18Inferior portion of the heartand the right ventriclethe ventricular septum and a large part of the left ventricular free walllateral wall of the left ventricleICUH

10、Institute of Cardiology Union Hospital19The occlusion of the coronary artery in experimental canine studies After clamping coronary artery, the initial ECG changes was an inversion of T wave. Ischemia is a reversible process unassociated with histologic changes. The clamp was left on the coronary ar

11、tery, the ischemia pattern persisted and the ST segment become elevated. The clamp was not released after the appearance of the injury stage, the elevated ST segment persisted, and the R wave disappeared and was replaced by Q wave. control clamping releasecontrol clamping clamping release control cl

12、amping clamping clamping release1. Ischemia stage ( reversible change )2. Injury stage ( reversible change )3. Infarction stage ( irreversible change )ICUHInstitute of Cardiology Union Hospital20心肌缺血（myocardial ischemia)心肌缺血主要影响心室复极（ST-T） ST-T的改变起决于缺血程度，持续时间和部位 表现为缺血型和损伤型 缺血型波改变 心内膜下缺血波高尖 机理缺血使心内膜复极

13、更慢，心内膜向量 减弱，心外膜波向量相对增加 心外膜下心肌缺血(含透壁) 波倒置 冠状波 机理心外膜缺血时，外膜复极缓慢，内膜相对较早复极，故复极顺序发生变化，由内向外，故波方向与正常相反，缺血导联记录到倒置波。ICUHInstitute of Cardiology Union Hospital21The ischemia ECG ( T wave change ) Subendocardial ischemia tall and upright T wave with prolonged Q-T interval Subepicardial ischemia deeply and symme

14、trically inverted T wave Transmural ischemia ( both subendo and subepicardial) the same as subepicardial ischemia ICUHInstitute of Cardiology Union Hospital22 缺血引起缺血引起T波改变的机制波改变的机制subendocardial ischemia Tall and upright T wave with prolonged Q-T interval exploring electrode; repolarization directio

15、n; T vector Subepicardial ischemiaepicardiumendocardiumNormal repola. Repola. delayed a time after the opposing repola. potentials from subepic. Repola. is delayed in subepicardium as compared to the subendocardium. The direction of the repola. process is reversed ( from endoc. To epic.) T.ICUHInsti

16、tute of Cardiology Union Hospital23损伤性损伤性ECG ( ST 段改变段改变 )心内膜心内膜 a horizontal depression of the ST segment Subepicardial injury the ST segment elevation Transmural injury ( both subendo and subepicardial injury ) the same as the subepicardial injure ICUHInstitute of Cardiology Union Hospital24损伤型 表现

17、为ST段压低或抬高 心内膜损伤：ST段压低 机理轻度损伤钾内流增加细胞内外钾浓度差加大细胞过度极化静息时损伤部电位较高T-P上抬，除极后损伤与正常部位无电位差，恢复等电位线，相对地ST段压低。 心外膜损伤： ST段抬高 机理 心肌损伤较重，细胞膜通透性增加，钾外逸，细胞内外钾浓度差减小，细胞极化不足，静息时损伤部电位较低，T-P下移，除极后损伤与正常部位无电位差，恢复等电位线，相对地ST段抬高。ICUHInstitute of Cardiology Union Hospital25Interpretation of injury pattern The injury ( ST ) vector

18、 points from normal area toward the injury area. Subendocardial injury The ST vector points from the epicardial toward the endocardial surface with ST segment depression.Subepicardial injury The ST vector points from the endocardial toward the epicardium surface with ST segment elevation.endocardium

19、epicardiumExploring electrodeICUHInstitute of Cardiology Union Hospital26ICUHInstitute of Cardiology Union Hospital27损伤型损伤型 ECG ( ST 改变改变 ) The acute phase:ST elevations and sometimes tall positive (hyperacute) T waves in certain leads. ICUHInstitute of Cardiology Union Hospital28ST-T改变的临床意义改变的临床意义l

20、冠脉灌注不足冠脉灌注不足 心绞痛的发作（短时间心绞痛的发作（短时间ST-T 改变改变 通常为压低通常为压低) 慢性冠脉缺血慢性冠脉缺血 (持续性持续性ST-T 改变改变 ) 变异性心绞痛变异性心绞痛( ST段抬高段抬高)lST 段抬高与压低相比，可能提示更为严重的缺血段抬高与压低相比，可能提示更为严重的缺血l鉴别诊断鉴别诊断 非特异性非特异性 ( 继发性继发性) ST-T 改变改变 原发性原发性ST-T 改变改变( 缺血缺血 ) ICUHInstitute of Cardiology Union Hospital29Angina pectoris 心绞痛心绞痛 a patient who co

21、mplained of chest pain while being examinedFive minutes later, after the patient was given sublingual nitroglycerin, the ST segments have reverted to normal, with relief of angina.the ECG with classic or typical angina often shows the pattern of subendocardial ischemia with ST segment depressions.IC

22、UHInstitute of Cardiology Union Hospital30Angina pectoris 心绞痛心绞痛 A Baseline rhythm strip from the positive exercise test of a patient with coronary artery disease.Notice the marked ST depressions with increased heart rate. ICUHInstitute of Cardiology Union Hospital31Variant angina pectoris 变异性心绞痛Sev

23、eral hours later, (after nitroglycerin ) completely normal ECG recurrent chest pain at rest, marked elevation of the ST in leads II, III, aVF, by reciprocal ST depression in leads I, and aVL. Non-specific ST-Tchange inferior leadsTheir angina is atypical because, they have ST segment elevations.ICUH

24、Institute of Cardiology Union Hospital32Other conditions can produce ST-T changes Secondary T wave change : myocarditis, cardiomyopathy, pericarditis, electrolyte imbalance, drug use, ventricular hypertrophy, bundle-branch block, W-P-W syndrome, et al. Primary T wave change : characteristic ECG find

25、ings of myocardial ischemia ICUHInstitute of Cardiology Union Hospital33Other conditions can produce ST-T changesST segment elevation, usually most marked in the chest leads, is sometimes seen as a normal variant. This so-called early repolarization pattern may be confused with the ST segment elevat

26、ions of acute myocardial infarction or pericarditis.ICUHInstitute of Cardiology Union Hospital34Characteristic morphologic features of secondary and primary T wave changes J pointICUHInstitute of Cardiology Union Hospital35Myocardial infarction心肌梗死心肌梗死ICUHInstitute of Cardiology Union Hospital36心肌梗死

27、（myocardial infarction）心肌梗死是冠心病的严重类型，为心肌的缺血性坏死。其发生包括缺血，损伤和坏死三个类型，在ECG上有特征性的演变过程。缺血型改变 表现为T波的高尖（内膜）或倒置（外膜） 机理同前损伤型改变 由于损伤严重，故表现为ST段上抬 机理 舒张期损伤电流学说 （同前） 除极波受阻学说 损伤除极不完全（表面电位为正）而此时正常心肌表面电位为负，损伤部电位较高，面对损伤部的电极出现ST抬高 ICUHInstitute of Cardiology Union Hospital37损伤型损伤型 ECGConvex upward ST elevation In trans

28、mural AMI, ST change is the same finding as a pure subepicardial injury ( monophasic wave ). Plateau shapeDome shape Monophasic waveICUHInstitute of Cardiology Union Hospital38Interpretation of injury patternSystolic current of injury收缩期损伤电流Diastolic current of injury舒张期损伤电流ICUHInstitute of Cardiolo

29、gy Union Hospital39Two theories to explain ST elevation1. 舒张期损伤电流学说舒张期损伤电流学说 ( the resting state ): diastolic current of injury The normal area of completed polarization. (+) The injured area of incomplete polarization. ()The exploring lead facing opposite to the injury vector; Injury deflection bel

30、ow the baseline 2. 除极受阻学说除极受阻学说 ( 去极化去极化 ): systolic currentThe normal area of complete depolarization. ()The injury area of blocking of depolarization. (+) The ST vector points to the exploring lead, an elevated ST is produced.Reciprocal ST depressions can appear in leads sensing the contralateral

31、surface of the heart. Resting depolarization repolarization Resting depolarization repolarizationBase lineBase lineICUHInstitute of Cardiology Union Hospital40坏死型改变坏死型改变MI诊断的标志诊断的标志 abnormal Q wave and diminished amplitude or absence of the R wave in the leads facing the necrotic or scarred myocardi

32、um.坏死型坏死型Q 波的诊断标准波的诊断标准 Width of Q wave 0.04 sec Depth of Q wave R waveICUHInstitute of Cardiology Union Hospital41坏死型坏死型Q波的发生机理波的发生机理 infracted Q wave is the resultant vector of both infracted and uninfracted myocardium. Most MI are located in the LV free wall and the ventricular septum. The initia

33、l vector of myocardial depolarization changes. Sequence of depolarization in the normal myocardium Sequence of depolarization in infarcted myocardium An initial q wave ( septal depolarization ) is part of the normal LV morphology. Resultant vector of the free both ventricular wall Necrotic zone beco

34、mes electrically inactive , the resultant vector points away from the necrotic zone.qICUHInstitute of Cardiology Union Hospital42Q 和和 QR 取决于记录电极的位置取决于记录电极的位置 The exploring electrode is placed directly over a transmural infarcted area, no R wave, but QS wave. The exploring electrode is placed over an

35、 area where the endocardial surface is infarcted, but epicardial surface is not . So a QR wave is present, and the amplitude of the R wave is small.ICUHInstitute of Cardiology Union Hospital43直接的心表电极记录直接的心表电极记录ICUHInstitute of Cardiology Union Hospital44 胸导联记录胸导联记录 Precordial lead close to ischemic

36、and injured zone Precordial lead close to necrotic, injured and ischemic zoneICUHInstitute of Cardiology Union Hospital45心肌梗死ECG的演变及分期分期 时间 心电图表现早期（超急性期） 数分 ST抬高T高大无Q急性期 小时日周 T下降倒置 ST抬高下降 Q波出现近期（亚急期） 数周月 ST段正常Q波 T波改变陈旧期（愈合期） 3-6月后 ST-T正常或T稍异常Q波ICUHInstitute of Cardiology Union Hospital46 Evolution o

37、f MI 心肌梗死的演变心肌梗死的演变 Minutes later, perisiting hours Tall, peaked, broad T wave;ST elevation.Hours or days later, perisiting weeks Abnormal Q or Qs; ST elecvation; inverted T. weeks monthsAbnormal Q or QS;ST retuning to base line;Deeply inverted T.36 months after MI.Q may or may not disappear;T norma

38、l or inverte.Onset of AMINormal hyperacute acute stage subacute (recent ) stage old stageICUHInstitute of Cardiology Union Hospital47Clinical significance of evolution of MIThe characteristic Q, ST, and T changes of MI frequently do not occur simultaneously in the same ECG and should be followed by

39、the means of serial tracings, which are extremely important for accurate diagnosis of AMI.Progressive changes in the ST, T, QRS configuration are the hallmark of AMI.ICUHInstitute of Cardiology Union Hospital48心肌梗死的定位根据Q波出现的导联定位ICUHInstitute of Cardiology Union Hospital49Inferior portion of the hear

40、tand the right ventriclethe ventricular septum and a large part of the left ventricular free walllateral wall of the left ventricleICUHInstitute of Cardiology Union Hospital50the anterior portion of the left ventriclethe inferior portion of the left ventricle Localization of infarctionICUHInstitute

41、of Cardiology Union Hospital51 Localization of infarctionDetermined by recognizing abnormalities ( abnormal Q or QS ) in the leads facing the damaged area.Expressed for the diagnosis of MI three major locations anterior（前壁）（前壁）, inferior ( diaphramatic )（下壁）（下壁）, posterior（后壁）（后壁）. anterior MI furth

42、er divided into anteroseptal（前间壁）（前间壁）, localized anterior（前壁）（前壁）, anterlateral（前侧壁）（前侧壁）, extensive anterior （广泛前壁）（广泛前壁） The electrocardiographic locations of MI do not correlate precisely with pathologic findings.ICUHInstitute of Cardiology Union Hospital52导联 前间壁 前壁 前侧壁 高侧壁 广泛前壁 下壁 后壁 右室 V1 + +

43、V2 + + + V3 + + + V4 + + + V5 + + V6 + + V7 + V8 + V9 + + + + + avL + + aVF + V3R + V4R + V5R + V6R +ICUHInstitute of Cardiology Union Hospital53Localization of anterior infarctionsaVL Anteroseptal MI 前间壁前间壁 V1 3 Anterior ( localized ) MI 前壁前壁 V2 4 Anterolateral MI 前侧壁前侧壁 I, aVL, V4 6 High lateral M

44、I 高侧壁高侧壁 I, aVL Extensive anterior MI 广泛前壁广泛前壁 I, aVL, V16左心室高侧心尖高间中间右心室V3V2V1V4V5V6IICUHInstitute of Cardiology Union Hospital54ECG sequence with anterior wall Q wave infarctionA, Acute phase of an anterior wall infarction: ST elevations and new Q waves. B, Evolving phase: deep T wave inversions. C

45、, Resolving phase: partial or complete regression of ST-T changes (and sometimes of Q waves). In A and B, notice the reciprocal ST-T changes in the inferior leads (II, III, and aVF). ICUHInstitute of Cardiology Union Hospital55ECG sequence with inferior wall Q wave infarction A, Acute phase of an in

46、ferior wall myocardial infarction: ST elevations and new Q waves. B, Evolving phase: deep T wave inversions. C, Resolving phase: partial or complete regression of ST-T changes (and sometimes of Q waves). In A and B, notice the reciprocal ST-T changes in the anterior leads (I, aVL, and V2). ICUHInsti

47、tute of Cardiology Union Hospital56Evolution of acute anterior wall MI TTTTQ STQ STSTSTSTIn the earliest phase of the infarctionSeveral hours laterICUHInstitute of Cardiology Union Hospital57Evolution of acute extensive anterior MIICUHInstitute of Cardiology Union Hospital58Evolution of acute inferi

48、or MI12 Hours after onset of chest pain24 Hours later5 Days later Markedly elevated ST in leads II, III, aVF. Reciprocal ST depression in leads ( I, aVR, aVL, V14 ) facing the undamaged area during the acute phase. Q wave and inverted T waves in II，III，aVF ICUHInstitute of Cardiology Union Hospital5

49、9Recent inferior MIThis patient sustained a myocardial infarction 1 month previouslyICUHInstitute of Cardiology Union Hospital60Old inferior MI Notice the prominent Q waves in leads II, III, and aVF from a patient who had a myocardial infarction 1 year previously. The ST-T changes have essentially r

50、everted to normal. ICUHInstitute of Cardiology Union Hospital61Anterior wall and inferior MINotice the slow R wave progression and QS complexes in chest leads V1 to V5, as well as the QS waves in leads II, III, and aVF.ICUHInstitute of Cardiology Union Hospital62Non-Q wave myocardial infarctionSuben

51、docardial infraction markedly depressed ST in many leads The ECG changes: ST elevation or depression; T wave inverted; without abnormal Q wave; ST T evolution. NonQ wave infarction in a patient who complained of severe chest pain. Subsequently, the patients cardiac enzyme levels were elevated. Notic

52、e the marked, diffuse ST depressions in leads I, II, III, aVL, aVF, and V2 to V6, in conjunction with the ST elevation in lead aVR. These findings are consistent with severe subendocardial ischemia. ICUHInstitute of Cardiology Union Hospital63MI complicated by ventricular aneurysm 室壁瘤Notice the prominent Q waves in leads V1 to V3 and aVL, the persistent ST elevations in these leads, and the reciprocal ST depressions in the inferior leads (II, III, and aVF).The diagnosis is confirmed by cardiac catheterization. ICUHInstitute of Cardio