心电图介绍ppt课件

1、QuestionsWhy ECG could be served for the diagnosis of some diseases?What is ECG? What is normal ECG?A. Basic knowledge of ECG Depolarization and repolarization Single myocardial cell A muscle strip 心脏传导系统接受迷走-交感神经支配 The normal Sinus Node Rhythm3. Pacing and conducting system of the heartSinus node I

2、nternodal tracts AV node r i g h t b u n d l e b r a n c h ( R B B ) Purkinje fibersBundle of His a n t e r i o r fascicle l e f t b u n d l e b r a n c h ( L B B ) Purkinje fibers p o s t e r i o r fascicle电轴w临床任务中很少丈量P波和T波的电轴，而QRS波群的电轴变化常与心脏病变亲密相关。w电轴的正常值在-30+90度，-30-90度电轴左偏，+90+180电轴右偏，-90+180度电轴

3、不确定STST段段 在任一导联在任一导联STST段下移不超越段下移不超越0.05mv0.05mv，STST段段上抬在上抬在V1-V2V1-V2导联不超越导联不超越0.3mv,V30.3mv,V3不超越不超越0.5mv 0.5mv V4-V6V4-V6与肢体导联不超越与肢体导联不超越0.1mv0.1mv。T T波波1 1方向：大多和方向：大多和QRSQRS主波的方向一致。假主波的方向一致。假设设V1V1的的T T波向上，那么波向上，那么V2-V6V2-V6导联就不应再向下。导联就不应再向下。 2 2振幅：除振幅：除、aVLaVL、aVFaVF、V1-V3V1-V3导联外，导联外，T T波的振幅普

4、通不应低于同导联波的振幅普通不应低于同导联R R波的波的1/101/10。T T波波在胸导联有时可高达在胸导联有时可高达1.2-1.5mv1.2-1.5mv尚属正常。尚属正常。Q-TQ-T间期间期 正常范围为正常范围为0.32-0.44S0.32-0.44S。Q-TcQ-Tc就是就是R-RR-R间期为间期为1s(1s(心率心率6060次次/ /分时的分时的Q-TQ-T间期。间期。Q-TcQ-Tc的的正常上限为正常上限为0.44S0.44S。U U波波 U U波方向大体与波方向大体与T T波相一致。波相一致。U U波明显增高波明显增高见于血钾过低。见于血钾过低。Part III Part III

5、 Atrial Enlargement and Atrial Enlargement and Ventricular Hypertrophy Ventricular Hypertrophy(1) Left Atrial Enlargement(1) Left Atrial EnlargementLead IILead IIDuration of P wave 0.12 sec. ;Duration of P wave 0.12 sec. ;P wave become bifid (P mitrale);P wave become bifid (P mitrale);The distance o

6、f two peak 0.04sec.The distance of two peak 0.04sec. Lead V1 Lead V1P wave become biphasic;P wave become biphasic;Ptfv1 Ptfv1 - 0.04 mmsec - 0.04 mmsecRight Atrial EnlargementRight Atrial EnlargementLead IILead II P wave is peaked (P pulmonale); P wave is peaked (P pulmonale); Amplitude of P wave 0.

7、25 mV in limb leads. Amplitude of P wave 0.25 mV in limb leads.Biatrial Enlargement Biatrial Enlargement Lead IILead II P wave duration and amplitude P wave duration and amplitude both increased. both increased.Left Ventricular HypertrophyLeft Ventricular HypertrophyA. Increased voltage A. Increased

8、 voltage SV1 + R V5 3.5mV (female), 4.0mV (male); SV1 + R V5 3.5mV (female), 4.0mV (male); Rv5 or Rv6 2.5 mV; Rv5 or Rv6 2.5 mV; RI 1.5mV; RI 1.5mV; RaVL 1.2mV; RaVL 1.2mV; RaVF 2.0 mV; RaVF 2.0 mV; RI + SIII 2.5 mV; RI + SIII 2.5 mV;B. Left axis deviation B. Left axis deviation C. ST depression and

9、 T inversion in V5-6.C. ST depression and T inversion in V5-6.Right Ventricular HypertrophyRight Ventricular HypertrophyA. Increased voltage (adults over 30)A. Increased voltage (adults over 30) R/S ratio in V1 1.0; R/S ratio in V1 1.0;R/S ratio in V5 or V6 1.0;R/S ratio in V5 or V6 1.0;R/q or R/S r

10、atio in aVR1;R/q or R/S ratio in aVR1;R V1+ S V5 1.05mV (severe1.2mV); R V1+ S V5 1.05mV (severe1.2mV); RaVR0.5mV;RaVR0.5mV;B. Right axis deviation +900 (severe +1100).B. Right axis deviation +900 (severe +1100).C. ST depression and T inversion V1-2.C. ST depression and T inversion V1-2.Part VI Part

11、 VI Myocardial Ischemia and Myocardial Ischemia and Myocardial infarctionMyocardial infarctionECG of myocardial ischemia shows:ECG of myocardial ischemia shows:wST segment depression;ST segment depression;wST segment elevation( coronary spasm);ST segment elevation( coronary spasm);wInverted, diphasi

12、c, low T wave. Inverted, diphasic, low T wave. Myocardial infarction Myocardial infarction (1) Basic changes “Hyperacute T Waves. Tall peaked T waves, often appear as the earliest ECG sign of acute MI. ST Elevations. The ST segment elevated in one or more leads and may be straightened and fuse with

13、the T wave (mono-phasic curve) Pathologic Q Waves. the sudden developed Q wave may indicate an acute MI. w T Wave Changes. The elevated ST segments return to the baseline, and deep symmetrical T waves appear in these leads. Tall, symmetrical, upright T waves will appear in reciprocal leads at the same time.(2) Progressive ECG changes(2) Progressive ECG changes (3) Localization of the ECG patterns Leads with Abnormal Q Waves in MILeads with Abnormal Q Waves location of MI V1 V3 Anteroseptal V3 V5 Anterior I, aVL, V5 V6 Lateral V1 V6 Extensive Anterior II, III, aVF Inferior (4