《【诊断学课件】器械检查部分：心电图基础.doc》由会员分享，可在线阅读，更多相关《【诊断学课件】器械检查部分：心电图基础.doc（4页珍藏版）》请在taowenge.com淘文阁网|工程机械CAD图纸|机械工程制图|CAD装配图下载|SolidWorks_CaTia_CAD_UG_PROE_设计图分享下载上搜索。
1、 第四篇 器械检查第一章 心电图Electrocardiogram 吕卓人 第一节? 临床心电学的根本知识 第二节 心电图的测量和正常值 1了解心电图产生的原理 2熟悉常用导联、正常心电图各波的图像、正常参考值 3熟悉有关心电图诊断的常用英语词汇 Questions Why ECG could be served for the diagnosis of some diseases? How does ECG work? What is ECG? What is normal ECG? A real case with chest pain diagnosis A. Basic knowled
2、ge of ECG 1. Depolarization and repolarization Single myocardial cell A muscle strip 2. Vector and resultant vector 3. Pacing and conducting system of the heart Sinus node? Internodal tracts? AV node ? right bundle branch (RBB) Purkinje fibers Bundle of His anterior fascicle left bundle branch (LBB)
3、 Purkinje fibers posterior fascicle 4. Lead system ? Limb leads: Standard leads: I, II, III ? Limb leads: aVR, aVL, aVF Hexaxial system Chest leads: V1, V2, V3, V4, V5, V6, V7, V8, V9 B. Normal ECG P wave PR interval QRS complex ST segment T wave QT interval U wave 1.? Measurement of ECG waves and i
4、ntervals ? ECG paper ? Measuring heart rate (HR) = 60/R-R (bpm) regular or irregular rhythm ? Amplitude of waves or segment: P, QRS, S-T, T, U ? Width or duration of waves: P, QRS, T, U ? Duration of intervals: P-R, Q-T ? Shape of waves: P, QRS, T 2. Mean QRS axis l normal cardiac axis range from -3
5、0?90? l significant left deviation: -30?-90? L right deviation: 90?180? L significant right deviation: 180?-90? 3. Clockwise and counterclockwise rotation l? Clockwise rotation ? Counterclockwise rotation 4. Normal ECG (1) P wave: atrial depolarization l? Amplitude ? 0.20 mv l? Duration ? 0.11 sec l
6、? Positive in I, II, aVF, V4-V6; Negative in aVR (2) PR interval: the time for intraatrial, AV nodal, and His-Purkinje conduction, Duration: 0.12 0.20 sec (3) QRS complex: ventricular depolarization l?The width: 0.06?0.10 sec, ? 0.11 sec. l?From V1 to V6, the R waves gets bigger and bigger, the S wa
7、ves gets smaller and smaller. l?R/S l in V1, but R/S l in V5 l?R in V5 and V6 2.5 mv, R in V1 1.0 mv l?R in aVR 0.5 mv, l?R in aVL 1.2 mv and R in aVF 2.0 mv l?R in I 1.5 mv l? Q 0.04 sec in width, 1/4 R in the same lead. (4) ST segment: it reflects Phase 2 of the action potential. l?ST elevation 0.
8、3 mV in V1、V2; 0.5 in V3, 0.10 mV in V4 ? V6 l?ST depression 0.05 mV in any leads (5) T wave: repolarization of ventricles It is upright in all the unipolar leads except aVR, and occasionally V1. T wave 1/10 R in the same lead, maybe 1.2?1.5 mV in the precordial leads (6) QT interval: the duration o
9、f depolarization and repolarizaion of ventricles. The normal range is 0.32?0.44 sec. (7) U wave: the wave following the T wave and is usually very small. Its cause is not completely understood. Elevated U wave: low K+ in plasma C. Summary Why ECG could be served for the diagnosis of some diseases? H
10、ow does ECG work? What is ECG? What is normal ECG? 1. Basic knowledge of ECG(electrocardiogram) Depolarization and repolarization: Vector and resultant vector Pacing and conducting system of the heart Lead system: (Limb leads) I, II, III, aVR, aVL, aVF, (Chest leads) V1, V2, V3, V4, V5 2. Normal ECG
11、: P wave, QRS complex, T wave, U wave, PR interval, QT interval, ST segment, R-R (P-P) Mean QRS axis Clockwise and counterclockwise rotation Normal value and shape: l?Amplitude of waves or segment: P, QRS, T, U and S-T l?Width or duration of waves: P, QRS, T, U l?Duration of intervals: P-R, Q-T l?Sh
12、ape of waves: QRS, T Clinical significances of abnormal ECG TEST in classroom Please translate the following words into Chinese: PRACTICE Make an ECG by yourself first. Read and measure your ECG with correct way and steps. Is your ECG normal or abnormal? Keep your ECG for memory. It is the first time as a doctor to make ECG and diagnosis! Good beginning is the half of success! * * *