Post on 17-Jan-2016
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Electrocardiogram (ECG)
Guyton
2011
Chapter 11
Session 5
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Electrocardiogram
What is the ECG?
How the ECG was recorded?
What are the characteristics of ECG paper?
What are the waves, intervals and segments of ECG?
What is lead?
How many lead are usually recorded?
What is the Einthoven law?
What is vector?
What can we earn from ECG?
Objects
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Electrocardiogram
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Electrocardiogram
Atrial contraction
BeginsComplet
e
Ventricular contraction
BeginsComplet
e
Ventricular Relaxation
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Electrocardiogram
Recording of the ECG
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Recording of the ECG
Electrocardiogram
Depolarization
Begins
Complete
Repolarization
Begins
Complete
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Flow of Current Around the Heart During the Cardiac Cycle
Electrocardiogram
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Flow of Electrical Currents in the Chest Around the Heart
Electrocardiogram
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Electrocardiogram
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Electrocardiogram
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Time (s) Voltage (mv) Wave or complex and
interval
0.1 - 0.3 P
1 - 1.5 QRS
0.2-0.3 T
0.16 PQ (PR)
0.35 QT
Electrocardiogram
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Heart Rate Determination from ECG
squares small ofnumber the
1500 RateHeart
squares large ofnumber the
300 RateHeart
60 inteval RR
1 RateHeart
Electrocardiogram
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Electrocardiographic Leads
Electrocardiogram
Bipolar Limb Leads
Unipolar Limb Leads
Chest Leads (PrecordiaI Leads)
I
II
III
aVR
aVL
aVF
V1
V2
V3
V4
V5
V6
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Electrocardiographic Leads
aVF
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Electrocardiographic Leads
Standard Bipolar
Limb Leads
Electrocardiogram
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Standard Bipolar Limb Leads
Electrocardiogram
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Einthoven's LawI + III = II
Electrocardiogram
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Electrocardiogram
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Vectorial Analysis of Electrocardiograms
Electrocardiogram
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Unipolar Limb Leads
Electrocardiogram
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Vectorial Analysis of Electrocardiograms
Electrocardiogram
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Electrocardiographic Leads (Horizontal plane)
Electrocardiogram
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The anatomical orientation of the heart
The relative sizes of its chambers
The various disturbances of rhythm
Conduction, the extent and location of ischemic
damage to the myocardium and its progress
The effects of altered electrolyte concentrations
The influence of certain drugs (notably digitalis,
antiarrhythmic agents, and Ca++channel antagonists).
Electrocardiogram
Findings from ECG
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The End