心电图教学英文版.ppt

Clinical ElectrocardiographyTeaching Course 苏州大学附属二院心内科 邵春来 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 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） 同一轴axile的二个心电向量的方向相同者，其幅度argument相加； Vectors may be summed by parallelogram method to produce Resultant Vector （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 branches Purkinje 纤维网 Purkinje system 2 （四）心电图导联  leads of the ECG 双极肢体导联 bipolar extremity 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 Paper Device Paper Speed Device Calibration Electrode Placement EKG Paper Standardized Methods Devices ECG Graph Paper Vertical axis- millivolt 1 small box = 1 mm = 0.1 mV Horizontal axis - time 1 small box = 1 mm = 0.04 sec. Standardized Methods Devices Paper Speed Calibration Paper Speed - 25 mm/sec standard Calibration of Voltage is Automatic Both Speed and voltage calibration can be changed on most devices What is the heart rate? 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. （二） Components of the ECG Components of the ECG Complex P Wave first upward deflection represents atrial depolarization usually 0.10 seconds or less usually followed by QRS complex Components of the ECG Complex QRS Complex Composition of 3 Waves Q, R S represents ventricular depolarization much variability usually 0.12 sec Components of the ECG Complex Q Wave first negative deflection after P wave depolarization of septum not always seen Components of the ECG Complex R Wave first positive deflection following P or Q