Transcript ECG Presentation

Anatomy
ECG Electrodes
ECG Waveform
The 12 lead ECG
How does the heart work
AV node activated by Atrial depolarization
Sends signal through His-purkinje bundle
Get depolarization of SEPTUM
Left and Right BUNDLES transmit signal
to Left and Right VENTRICLES
Net “Vector” towards the LV
Should be narrow (<120msec) if bundles
working properly
Then have REPOLARIZATION
= Twave
The appearance of this electrical activity
depends on which lead you are using to
look at it
Review of waveforms
How to Look at an ECG
• Rate:
• Rhythm:
• Axis:
•
•
•
•
•
Is the heart rate too fast or slow?
Sinus rhythm or not?
Where does the majority of
electrical activity point?
P wave:
How big are the atria?
PR interval:
How healthy is the AV node?
QRS wave:
Is there abnormal conduction
or a ventricular source?
QT:
Long is bad
Ischemia and hypertrophy
ECG Paper
Can Determine Heart Rate
Rule: 300, 150, 100, 75, 60, 50 counting over for each big sqaure
What is the heart rate?
Answer = 75 per min
Rhythm :
Is there a p wave? = Sinus
Is it followed by a QRS?
Is the rhythm regular or irregular?
Reasons to have an irregular rhythm
• Irregular pacemaker
– Multifocal atrial
rhythm
– Atrial fibrillation
– Atrial fib/flutter
• Ectopic beats
– PVC
– PAC
– PJC
• Irregular conduction
– AV node block
• 1st degree:
– PR interval > 200 msec
• 2nd degree:
– Type 1: Wenkebach
– Type 2: dropped beat
• 3rd degree:
– p waves marching
independent to QRS
Examples of Rhythms
Multifocal
Atrial Rhythm
AFIB
Atrial Flutter
AFIB
V TACH
Example of a PVC
Telling the Axis from the leads
The axis wheel
The P wave
The QRS
QRS < 120 msec
QRS > 120 msec
Rabbit ears in V1 & V2
Wide S wave in V5 & V6
R axis deviation
QRS > 120 msec
Deep slurred S wave in V1
Wide R wave in V6, I & avL
L axis deviation
Ishcemia vs Acute Infarct
Example of Ischemia
Examples of Infarctions
Review
• Rate:
• Rhythm:
• Axis:
•
•
•
•
•
Is the heart rate too fast or slow?
Sinus rhythm or not?
Where does the majority of
electrical activity point?
P wave:
How big are the atria?
PR interval:
How healthy is the AV node?
QRS wave:
Is there abnormal conduction
or a ventricular source?
QT:
Long is bad
Ischemia and hypertrophy
Describe this ECG
Describe this Strip