心电图介绍-李宁.ppt

心电图介绍-李宁
Questions
Why ECG could be served for the diagnosis of some diseases?
What is ECG? What is normal ECG?
;
 RaVL > ;
 RaVF > mV;
 RI + SIII > mV;
B. Left axis deviation
C. ST depression and T inversion in V5-6.
Right Ventricular Hypertrophy
A. Increased voltage (adults over 30)
R/S ratio in V1 > ;
R/S ratio in V5 or V6 ≤ ;
R/q or R/S ratio in aVR≥1;
R V1+ S V5 > (severe>);
RaVR>;
B. Right axis deviation ≥ +900 (severe > +1100).
C. ST depression and T inversion V1-2.
Part VI Myocardial Ischemia and Myocardial infarction
ECG of myocardial ischemia shows:
ST segment depression;
ST segment elevation( coronary spasm);
Inverted, diphasic, low T wave.
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 the T wave (mono-phasic curve)
Pathologic Q Waves. the sudden developed Q wave may indicate an acute MI.
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
(3) Localization of the ECG patterns
Leads with Abnormal Q Waves in MI
Leads 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) O