心電圖介紹李寧文檔資料

1、questionswwhy ecg could be served for the diagnosis of some diseases?wwhat is ecg? what is normal ecg?a. basic knowledge of ecg depolarization and repolarizationw single myocardial cellw a muscle strip 心臟傳導(dǎo)系統(tǒng)接受迷走-交感神經(jīng)支配 the normal sinus node rhythm3. pacing and conducting system of the heartsinus no

2、de internodal 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電軸w臨床工作中很少測(cè)量p波和t波的電軸，而qrs波群的電軸變化常與心臟病變密切相關(guān)。w電軸的正常值在-30+90度，-30-90度電軸左偏，+90+180電軸右偏，-90+18

3、0度電軸不確定stst段段 在任一導(dǎo)聯(lián)st段下移不超過0.05mv，st段上抬在v1-v2導(dǎo)聯(lián)不超過0.3mv,v3不超過0.5mv v4-v6與肢體導(dǎo)聯(lián)不超過0.1mv。t t波波（1）方向：大多和qrs主波的方向一致。若v1的t波向上，則v2-v6導(dǎo)聯(lián)就不應(yīng)再向下。 （2）振幅：除、avl、avf、v1-v3導(dǎo)聯(lián)外，t波的振幅一般不應(yīng)低于同導(dǎo)聯(lián)r波的1/10。t波在胸導(dǎo)聯(lián)有時(shí)可高達(dá)1.2-1.5mv尚屬正常。q-tq-t間期間期 正常范圍為0.32-0.44s。q-tc就是r-r間期為1s(心率60次/分）時(shí)的q-t間期。q-tc的正常上限為0.44s。u u波波 u波方向大體與t波相一致

4、。u波明顯增高見于血鉀過低。part iii part iii atrial enlargement andatrial enlargement and ventricular hypertrophy ventricular hypertrophy(1) left atrial enlargement(1) left atrial enlargementlead iilead iiwduration of p wave duration of p wave 0.12 sec. ;0.12 sec. ;wp wave become bifid (p mitrale);p wave become

5、bifid (p mitrale);wthe distance of two peak the distance of two peak 0.04sec.0.04sec. lead v lead v1 1p wave become biphasic;p wave become biphasic;ptfvptfv1 1 - 0.04 mm - 0.04 mmsecsecright atrial enlargementright atrial enlargementlead iilead iiw p wave is peaked (p pulmonale); p wave is peaked (p

6、 pulmonale);w amplitude of p wave 0.25 mv in limb leads. amplitude of p wave 0.25 mv in limb leads.biatrial enlargementbiatrial enlargement lead iilead ii p wave duration and amplitude p wave duration and amplitude both increased. both increased.left ventricular hypertrophyleft ventricular hypertrop

7、hya. increased voltage a. increased voltage w s sv1v1 + r + r v5 v5 3.5mv (female), 4.0mv (male); 3.5mv (female), 4.0mv (male);w rv rv5 5 or rvor rv6 6 2.5 mv; 2.5 mv; r ri i 1.5mv; 1.5mv; r ravl avl 1.2mv; 1.2mv; r ravfavf 2.0 mv; 2.0 mv; r ri i + s + siiiiii 2.5 mv; 2.5 mv;b. left axis deviation b

8、. left axis deviation c. st depression and t inversion in vc. st depression and t inversion in v5-6.5-6.right ventricular hypertrophyright ventricular hypertrophya. increased voltage (adults over 30)a. increased voltage (adults over 30)w r/s ratio in v r/s ratio in v1 1 1.0; 1.0;wr/s ratio in vr/s r

9、atio in v5 5 or vor v6 6 1.0; 1.0;wr/q or r/s ratio in avr1;r/q or r/s ratio in avr1;r r v1 v1+ s+ s v5 v5 1.05mv (severe1.2mv); 1.05mv (severe1.2mv); r ravravr0.5mv;0.5mv;b. right axis deviation +90b. right axis deviation +900 0 (severe +110 (severe +1100 0). ).c. st depression and t inversion vc.

10、st depression and t inversion v1-2.1-2.part vi part 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 se

11、gment elevation( coronary spasm);winverted, diphasic, low t wave. inverted, diphasic, low t wave. myocardial infarctionmyocardial infarction (1) basic changes (1) basic changes w“hyperacute” t waves“hyperacute” t waves. tall peaked t waves, . tall peaked t waves, often appear as the earliest ecg sig

12、n of acute often appear as the earliest ecg sign of acute mi. mi. w st elevationsst elevations. the st segment elevated in . the st segment elevated in one or more leads and may be straightened one or more leads and may be straightened and fuse with the t wave (mono-phasic curve)and fuse with the t

13、wave (mono-phasic curve)w pathologic q wavespathologic q waves. the sudden developed . the sudden developed q wave may indicate an acute mi. q wave may indicate an acute mi. w t wave changest wave changes. the elevated st segments . the elevated st segments return to the baseline, and deep symmetric

14、al return to the baseline, and deep symmetrical t waves appear in these leads. tall, t waves appear in these leads. tall, symmetrical, upright t waves will appear in symmetrical, upright t waves will appear in reciprocal leads at the same time.reciprocal leads at the same time.(2) progressive ecg ch

15、anges(2) progressive ecg changes (3) localization of the ecg patterns leads with abnormal q waves in mileads with abnormal q waves in mileads with abnormal q waves location of mileads with abnormal q waves location of mi v v1 1 v v3 3 anteroseptalanteroseptal v v3 3 v v5 5 anterior anterior i, avl, v i, avl, v5 5 v v6 6 laterallateral v v1 1 v v6 6 extensive anterior extensive anterior ii, iii, avf inferior ii, iii, avf inferior (4)