EKG or ECG stands for:
electrocardiogram
What can an EKG detect?
cardiac arrhythmia or dysrhythmia, ischemia, electrolyte imbalance, effects of cardiac medications, damage caused by an MI
Define arrhythmia
abnormal cardiac rhythm (think a= without, without rhythm)
Define ischemia
lack of blood supply
What is the electrical pathway of the heart's conduction system?
SA node->AV node->Bundle of His->Right and Left Bundle Branches->Purkinje fibers
When the SA node is stimulated, what mechanical action happens in the heart?
Atria contract
What has to happen for the ventricles to contract?
Electrical conduction has to pass through the AV node, down the Bundle of His, through the right and left bundle branches, into the purkinje fibers. Once they reach the Purkinje fibers, then the ventricles will contract.
Electrodes
sticky skin sensors that attach to the patient
What is the purpose of the gel on the electrodes?
to read the heart's electricity and to amplify the waveforms
EKG machine is also called an:
electrocardiograph
Name the 2 types of EKG machines:
Single channel and multichannel
When we do an EKG we are looking at the heart from :
12 different points of view or angles
How many electrodes are used to perform an EKG?
10
What is an amplifier?
Magnifies the heart's electrical signal so it can be recorded.
What is the stylus?
records the motion on the graph paper by burning the impression into the heat-sensitive paper.
Name the limb leads.
RA, LA, LL, RL
What is unique about EKG paper?
It is head-sensitive and pressure-sensitive.
How big is a small block on EKG paper?
1mm x 1 mm
How big is a large block on EKG paper?
5mm x 5 mm
What speed does normal EKG paper run?
25mm per second
Why would a CCMA increase the speed of the EKG paper?
If the heart rate were very fast, the speed would be increased to 50mm per second.
How much TIME does each small square on EKG paper represent?
0.04 seconds
How much TIME does each large square on EKG paper represent?
0.2 seconds
What is another name for amplitude?
Gain
Define amplitude/gain.
how tall the tracing is. It is represented by 1x, 2x, or 3x.
How big is the normal amplitude/gain on an EKG?
2 large boxes or 10 small boxes
What is the purpose of standardization?
it is the process of making sure that an EKG on one machine will compare to the EKG on another machine.
What does the standardization mark look like?
Upside down U or a rectangle with the bottom out of it.
Name the chest or precordial leads (wires):
V1, V2, V3, V4, V5, V6
What are the leads RA, LA, RL, LL collectively called?
Limb leads
A 6 second strip in Lead II is called a
rhythm strip
Which lead (view) is a rhythm strip usually taken in?
Lead II
Which lead (wire) is always the ground
Right leg
Which 3 leads (views) make up Einthoven's Triange?
Lead I, II, and III
Which 3 leads (views) are the augmented leads?
AVR, AVF, AVL
Which leads (views) are the Precordial or Vector leads?
V1, V2, V3, V4, V5, V6
What education should you give to your patient before starting the EKG?
It is a non-invasive test that won't hurt, have to lie still, clothing should be removed from the waist up, no jewelry, gown open in the front. Any lotion needs to be removed with alcohol pads. Empty their bladder 10 minutes prior to the exam.
How should the patient be positioned when performing an EKG?
supine position, arms at the sides, or semi-fowlers
Where to do the limb leads go?
Right leg, Left leg, Right arm, Left arm
Where is V1 placed?
4th intercostal space on the right sternum
Where is V2 placed?
4th intercostal space on the left sternum
Where is V3 placed?
Between V2 and V4
Where is V4 placed?
Mid-clavicular line on the left side, 5th intercostal space
Where is V5 placed?
Anterior Axillary left side, 5th intercostal space
Where is V6 placed?
Mid-axillary line on the left side, 5th intercostal space
What order do you place the chest leads?
V1, V2, V4, V3, V5, V6
How are right-sided EKG leads placed?
Exactly the same as the left except on the right side.
What additional documentation must occur with the right-sided EKG?
Labeled with an "R".
Why would a right-sided EKG be done?
right-sided MIs, inferior MIs, patients less than 8 years old.
How are posterior EKG leads placed differently than a left sided EKG?
Limb leads and V1-V3 are the same. V4 = V7- posterior axillary line, V5=V8- midscapular line, V6=V9- left spinal border.
Why would a posterior EKG be ordered?
when a posterior MI is suspected
What does the P wave represent?
atrial depolarization (atrial contraction)
What does the QRS complex represent?
ventricular depolarization (ventricular contraction)
What does the T wave represent?
Ventricular repolarization (ventricular relaxation)
An elevation or depression of the ST segment can indicate what?
ischemia or injury to the heart muscle
What is the "normal" heart rhythm?
Normal sinus rhythm
What is a normal heart rhythm that is less than 60 bpm?
sinus bradycardia
What is a normal heart rhythm that is greater than 100 bpm?
sinus tachycardia
What are the two shockable, life-threatening cardiac rhythms?
Ventricular Tachycardia and Ventricular Fibrillation
What is a "flat line" rhythm?
asystole
What is the rhythm that has small "spikes" before the P wave or QRS complex?
Paced rhythm
What are the 3 ways we learned to calculate a heart rate on an EKG?
1500 method, Sequence method, 6-second rule
Explain the 1500 method.
Count the small boxes between R waves and divide by 1500
Explain the sequence method for calculating a heart rate
Use the big boxes and follow this sequence: 300, 150, 100, 75, 60. If the QRS falls between two large boxes, figure out the average.
Explain the 6-second method for calculating a heart rate.
Count the number of QRS complexes on a 6-second strip and multiple by 10.
What is a holter monitor?
An ambulatory ECG that monitors patients for 24-48 hours
What events should be documented in the diary of a patient wearing a holter monitor?
exercise, sexual activity, stressful events, emotional events, s/s of chest pain, SOB, dizziness.
What should be included in the documentation of a patient wearing a holter monitor?
Date, time, and what occurred during the event
What instructions should you tell your patient if they are wearing a holter monitor?
Wear loose clothing, do not shower or get it wet, use tape to help secure the leads if needed, if the leads come off-they must return to the physician's office.
What is a Cardiac Stress Test?
The patient exercises while wearing a monitor to determine if the heart is receiving enough blood during stressful events.
What are some potential complications of stress testing?
SOB, nausea, syncope (fainting), heart attack.
What equipment must be in the room during a stress test?
Emergency Equipment (crash cart): monitors, oxygen, defibrillator, intubation tray, ambu bag, emergency meds
If you don't know how to use your ECG machine or holter monitor, where should you look?
At the manufacturer's user manual
Define artifact.
abnormal waveform on an EKG tracing
Somatic Tremor
artifact caused by voluntary or involuntary muscle movement.
Wandering Baseline
when the tracing shifts from the baseline, usually caused by poor connection with the skin.
AC Interference
uniform spikes on an EKG caused by electrical interference.