ECG-Diagnosis.pdf
Transcript of ECG-Diagnosis.pdf
PRinterval
Mill
ivo
lts
Milliseconds
0 200 400 600
-0.5
0
0.5
1.0
P
R
T
Q
S
PR interval should be 120 to 200 milliseconds or 3 to 5 little squares
Mill
ivo
lts
Milliseconds
0 200 400 600
-0.5
0
0.5
1.0
QRS
P
R
T
Q
S
The width of the QRS complex should not exceed 110 ms, less than 3 little squares
I II III aVR aVL aVF V1 V2 V3 V4 V5 V6
The ST segment should start isoelectric except in V1 and V2 where it may be elevated
I II III aVR aVL aVF V1 V2 V3 V4 V5 V6
There should be no Q wave or only a small q less than 0.04 seconds in width in I, II, V2 to V6
ST segment elevation over area of damageST depression in leads opposite infarctionPathological Q wavesReduced R wavesInverted T waves
R
P
Q
ST
• Occurs in the early stages
• Occurs in the leads facing the infarction
• Slight ST elevation may be normal in V1 or V2
R
P
Q
T
ST
• Only diagnostic change of myocardial infarction
• At least 0.04 seconds in duration
• Depth of more than 25% of ensuing R wave
I II III aVR aVL aVF V1 V2 V3 V4 V5 V6 I II III aVR aVL aVF V1 V2 V3 V4 V5 V6
Anterior wall MI Left bundle branch block
1 minute after onset 1 hour or so after onset A few hours after onset
A day or so after onset Later changes A few months after AMI
Q
R
P
QT
STR
P
Q
ST
P
QT
ST
R
P
S
T
P
QT
ST
R
P
Q
T