心电图教学英文版优质PPT.ppt

1、Clinical ElectrocardiographyTeaching Course,苏州大学附属二院心内科 邵春来,Griffith Joyner38 years old died in 1998,Vivian fu 28 years old died in 2003,Marco Pantani35 years old died in 2004,心电图学基础（一）心电发生的原理basic principles of the electromechanics,（1）心肌静止时 resting myocardium（复极状态 repolarization status）,（2）心肌细胞受刺激

2、stimulated myocardium（从左到右开始除极 depolarization beginning from left to right）,（3）除极过程 process of depolarization（depolarization from left to right）,除极方向（-+）,1.,2.,3.,4.,Deplaorization Sequence of a“Strip”of 5 Myocardial Cells,Depolarization progressing from left to right,2.when depolarization spreads a

3、way from any lead,it produces a negative（downward）deflection in that lead.,1.when depolarization spreads toward any lead,it produces a positive（upward）deflection in that lead.,3.when depolarization spreads firstly toward and then away from any lead,it produces a biphasic deflection.,1）Vector,+,+,+,M

4、agnitudeDirectionfrom 0,An arrow represents two physical parameters:#direction and magnitude,2）resultant vector,0,同一轴axile的二个心电向量的方向相同者，其幅度argument相加；#,方向相反者则相减。#,A B C,A B C,Vectors may be summed by parallelogram method to produce Resultant Vector,=,Translate,=,Summed,Resultant Vector,The integrati

5、on can only be performed when the two vectors are generated at the same moment.,（二）心血管传导系统cardiovascular conduction system,心脏的传导系统由以下几部分组成,窦房结 SA node结间束 internodal atrial pathways房室结 AV node希氏束 AV bundle右束支 right bundle branches左束支 left bundle branchesPurkinje 纤维网 Purkinje system,SA node,AV node,两结

6、之间用vector表示,1,3,4,2,SA node,AV node,运用4原则记录心脏的vector传导过程位置不重要,1,2,3,4,不同部位记录电极的电位,In each cardiac cycle there are many instant vectors and if the tip of each vector is connected together a loop will be obtained,which is called as vector loop,such as QRS loop.,Various patterns of the ECG can be obtai

7、ned from the same vector loop.The pattern depends on the position of the electrode.,P,T,QRS,In the heart the vector loop,in fact,is a three-dimensional vector loop.,ECG,in nature,is double projections of a three-dimensional vector loop.,frontal plane,frontal plane,transverse plane,The three-dimensio

8、nal vector loop projects on a section of the body first.That is the vector loop of this section.,Then,the vector loop of the section projects on a lead.That is the ECG of this lead.,（四）心电图导联 leads of the ECG,双极肢体导联 bipolar extremity,RA,LA,LL,LARA，LLRA，LLLA,加压肢体导联 augmented extremity leads,aVR,aVL,aV

9、F,包括aVR、aVL、aVF导联,Lead v1:#4th intercostal space just to the right of the sternum,Lead v2:#4th intercostal space just to the left of the sternum,Lead v3:#a line midway between lead V2 and V4,Lead v4:#the mid-clavicular line in 5th intercostal space,Lead v5:#the anterior axillary line at the same lev

10、el as lead V4,Lead v6:#the mid axillary line at the same level as lead V4,angle of Louis,Totally different patterns of the potential（ECG）can be obtained from the same cardiac cycle.The potential（ECG）pattern depends on the position of the electrodes.,Now,you know,the ECG is a graphic recording of the

11、 electrical currents produced by the heart muscle during the atrial and ventricular depolarization and repolarization.,In summary,心电图的临床应用Clinical application of the ECG,（一）心电图的测量方法determination method of the ECG,Standardized Methods&#Devices,ECG PaperDevice Paper SpeedDevice CalibrationElectrode Pl

12、acement,Horizontal Axis,Vertical Axis,EKG Paper,Standardized Methods&#Devices,ECG Graph PaperVertical axis-millivolt1 small box=1 mm=0.1 mVHorizontal axis-time1 small box=1 mm=0.04 sec.,Standardized Methods&#Devices,Paper Speed&#CalibrationPaper Speed-25 mm/sec standardCalibration of Voltage is Auto

13、maticBoth Speed and voltage calibration can be changed on most devices,What is the heart rate?#,（300/6）=50 bpm,What is QRS Axis?#,The QRS axis is determined by overlying a circle,in the frontal plane.By convention,the degrees of the circle are as shown.,The normal QRS axis lies between-30o and+90o.,

14、A QRS axis that falls between-30o and-90o is abnormal and called left axis deviation.,A QRS axis that falls between+90o and+150o is abnormal and called right axis deviation.,A QRS axis that falls between+150o and-90o is abnormal and called superior right axis deviation.,Hexaxial array and ECG vector

15、s from various leads.Find net+or QRS in lead 1Find net+or _ QRS in Lead aVFResultant Vector.This is Mean Electrical Axis of Heart or Cardiac Vector.,Electrical axis is about+60o,Transitional zone（chest leads）,Represents the location of the lead,having positive and negative deflections of the same ma

16、gnitude.,Clockwise,normal,Counterclockwise,（二）Components of the ECG,Components of the ECG Complex,P Wavefirst upward deflectionrepresents atrial depolarizationusually 0.10 seconds or lessusually followed by QRS complex,When the atria are excited,this depolarizing electrical current can be recorded by ECG,and it is named P wave.,Components of the ECG Complex,QRS ComplexComposition of 3 WavesQ,R&#Srepresents ventricular depolarizationmuch variabilityusually 0.12 sec,Components of the ECG Complex,Q Wavefirst negat