Post on 24-Feb-2016
description
ELECTROCARDIOGRAM (ECG)
Cardiovascular System Physiology Lab
Interpretation Dr.Mohammed Sharique Ahmed Quadri
Asst. professor in physiology
الرحيم الرحمن الله بسم
ANALYZING INDIVIDUAL WAVES & SEGMENTS
P wave : upright except in avR Normal duration: 0.08 to 0.11 sec
do you see p waves ?are all p waves same ? does all QRS complexes have p waves ?
P-R interval : Normal range 0.12 – 0.20 sec Is the PR interval constant ? If prolong indicates various blocks
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ANALYZING INDIVIDUAL WAVES & SEGMENTS QRS complexes:
Are the p waves & QRS complexes are associates with each other
Are the QRS complexes narrow or wide
ST Segment : Normal : Isoelectric Elevation : in acute MI Depression : in ischemia
T wave: Tall T wave : ischemia, hyperkalemia Inverted : young children ,deep inspiration, bundle
branch block, ischemia,hypokalemia 3
ANALYZING INDIVIDUAL WAVES & SEGMENTS QT INTERVAL:
0.4 to 0.43 seconds depending upon heart rate.
At high heart rates, ventricular action
potentials shorten in duration, which decreases the Q-T interval.
. prolonged in acute MI ,hypocalcaemia
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Variation in ST segment
ST ELEVATION
One way to diagnose an acute MI is to look for elevation of the ST segment.
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ST ELEVATION SUGGESTIVE OF MI
ST ELEVATION (CONT)
Elevation of the ST segment (greater than 1 small box) in 2 leads is consistent with a myocardial infarction.
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PUTTING IT ALL TOGETHERDo you think this person is having a myocardial infarction. If so, where?
Yes, this person is having an acute anterior wall myocardial infarction.
Now, where do you think this person is having a myocardial infarction?
Inferior wall MI
How about now?
Anterior & lateral wall MI
NORMAL
HYPERKALEMIA
HYPOKALEMIA
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INTERPRETE THE ECG ?
HYPERKALEMIAObserve Tall T - wave
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REPORTING OF ECG
This ecg shows Sinus rhythm Heart rate of 75/ min Normal QRS axis Normal PR interval 0.12 sec Normal QRS duration 0.8 sec ST segment isoelectric in all leads T wave normal & upright in all wave except
in aVR 16
REFERENCES
Text book of medical physiology by GUYTON & HALL 11 th edition
Text book physiology by GANONG The ECG made Easy by John R.Hampton
sixth edition The guide to EKGinterpretation by
JohnA.Brose, D.O,John C.Auseon
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Prof. Magdy El-Barbary
Prof. Magdy El-Barbary
Suggestive of
Question NO:
What is the most likely cause of changes in ST seg. & T wave of each diagram?
ECG CHANGES
Ways the ECG can change include:
Appearance of pathologic Q-waves
T-waves
peaked flattened inverted
ST elevation & depression
REFERENCES Text book of medical physiology by
GUYTON & HALL 11 th edition Text book physiology by GANONG The ECG made Easy by John R.Hampton
sixth edition The guide to EKGinterpretation by
JohnA.Brose, D.O,John C.Auseon