Electrocardiography Flashcards
What does an electrocardiogram tell us?
- baseline snapshot of cardiac function
- evaluates symptoms of heart disease
- abnormal heart rhythms
- progress after heart attack
- side effects of certain medications
What is holter monitoring?
records electrical activity of the heart continuously over 24 hours or longer
What is stress testing for?
assesses patient’s blood and oxygen flow to the heart
What can stress testing diagnose?
medical conditions like coronary artery disease
What is heart rate?
number of times your heart beats per minute
What is heart rhythm?
synchronized pumping action of the four heart chambers
What is a steady heart rate?
60-100 beats per minute
What is sinus rhythm?
orderly contraction of the atria and ventricles
What is the pacemaker of the heart?
SA node
What is the cycle of a heartbeat?
- SA node sends out electrical impulse
- atria contracts
- av node sends impulse into the ventricles
- ventricles contract
- SA node sends out another impulse and cycle repeats
What are the proper equipment for EKG?
- 12-lead (10 electrodes on body, records activity from 12 angles)
- 3-lead
- single-channel
What is the y-axis for ekg paper?
gain/amplitude
What is the x-axis for ekg paper?
time
What does each grid on the x-axis mean?
0.04 seconds
What does each grid on a y-axis mean?
0.1 millivolts
Where should electrodes be placed if lower leg is amputated?
both sides of abdomen
Where should electrodes be placed if lower arm is amputated?
electrodes on upper arms
Where do the 10 leads go?
6 chest, 4 limb
Where does V1 lead go?
4th intercostal space, right of the sternum
Where does V2 lead go?
4th intercostal space, left of sternum
- across from V1
Where does V3 lead go?
midway between V2 and V4
Where does V4 lead go?
5th intercostal space
- midclavicular line
Where does V5 lead go?
5th intercostal space, between V4 and V6
- anterior axillary line
Where does V6 lead go?
5th intercostal space
- midaxillary line
What color is V1 lead?
red
What color is V2 lead?
yellow
What color is V3 lead?
green
What color is V4 lead?
brown
What color is V5 lead?
black
What color is V6 lead?
magenta
What color is right arm lead?
white
What color is left arm lead?
black
What color is left leg lead?
red
What color is right leg lead?
green
What does the P wave mean?
atrial depolarization/contract
What does the QRS wave mean?
ventricular depolarization/contraction
What does the T wave mean?
ventricular repolarization/relaxation
What does the U wave mean?
repolarization/relaxation of the bundle of His and Purkinje fibers
