Electrocardiography

Chapter 37
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what is the most common type of artifact
somatic tremor
example of somatic tremor from disease
Parkinson's
one cardiac cycle takes approximately how long
0.8 second
cardiac cycle aka
heart beat
part of wave that indicatates ventricular depolarization
QRS complex
another name for V leads is
precordial
what does P waves represent
atrial depolarization
another name for atrial depolarization
atrial contraction
repolarization
when the heart recovers and relaxes
when does repolarization occur
after contraction of heart muscle and the reestablishment of a polarized state
depolarization
contraction of cardiac cells
how does depolarization occur
with electrical activity from atria or ventricular contraction
what does QRS wave represent
ventricular contraction
what does the T wave represent
ventricular relaxation
medical term for ventricular relaxation
ventricular repolarization
which wave only occurs occasionally in some patients
u wave
what does the vertical line on the EKG represent
voltage
what does the horizontal line on the EKG represent
time
what is a baseline
flat horizontal line between cardiac cycle
what is one box equal to
.04 sec and 1 mm
what are 5 large squares equal to in time
.2 sec
what does BPM stand for
beats per minute
what is electrolyte
a conductive substance that contains moisture
what forms does electrolyte come in
gels, lotions, paste, presaturated pads and adhesive sensors
why is electrolytes necessary
because skin is a poor conductor of electricity
what are electrodes
a sensor that detects electrical impulse on the body surface
what are electrodes made of
metal or other conductive material
what are lead wires
metal wires carrying impulse from patient to machine
how can older electrocardiograph machines be adapted or converted to operate with the current self, adhesive electrodes?
alligator clips over end of lead wire tips ordered from manufacturer
how many sensors are on a standard EKG
10
how many leads do the sensors record
12
what are the sensors recording
the electrical impulses on the body surface
what are the four limb leads
left leg, left arm, right leg, right arm
which limb lead is called the "ground" or reference electrode
right leg
where on the lims are the sensors placed
fleshy , nonmuscular insides
lead I records the electrical activity between the....
right arm and left arm
lead II records the electrical activity between the
right arm and left leg
lead III records electrical activity between the....
left arm and left leg
which lead portrays the heart beat better then other leads
Lead II
Lead II aka
rhythm strip
the first 3 leads are also known as what type of lead
bipolar
leads iv, v, and vi are designated as what leads
aVR, aVL and aVF
these augmented leads are also known as what
unipolar
lead aVR records activity from
Right Arm and Right Leg
Lead aVL records activity from
Left Leg and Left Arm
lead aVF records activity from
foot
what does aVR, aVL and aVF stand for
augmented voltage right, left and foot
how long is each cardiac cycle
0.8 seconds
what does augmented mean
added to
how many sides does the heart have
2
how many lobes does the heart have
4
the skin is not a great conductor of ________
electricity
electrolytes provide __________ and electrodes provide _______ to the conduction process
moisture and metal
what is a two sided pump the routes blood where it needs to go
the heart
______ cells in the heart are able to conduct electricity
certain
artifacts are electrical __________
nuisances
what is it called when there is a discharge of electrical energy
depolarization
ECG is an
graphic representation of the heart's electrical activity
unipolar aka
augmented
a series of x-rays of a blood vessel after injection of a radiopaque substance
angiogram
the part of the heart cycle in which the heart is in contraction
systole
the flat, horizonatal line that separates the various waves of the ECG cycle
baseline
chemical substance that enhances the conduction of electrical activity
electrolyte
conversion of a pathologic cardia rhythm to normal sinus rhythm
carioversion
local and temporary lack of blood to an organ or a part because of obstruction of circulation
ischemia
procedure used to obtain cardia blood samples, detect abnormalities, and determine intracardiac pressure
cardiac catheterization
heated slender wire of the electrocardiograph that melts the wax off the ECG paper during the recording
stylus
pertaining to the area on the anterior surface of the body overlying the heart
precordial
procedures that do not require entering the body or puncturing the skin
noninvasive
sensors used to conduct electricity from the body to the electrocardiograph
electrodes
to add or increase
augmented
process of applying in sequence a protion of each of the 12 leads of the ECG recording onto a document placed in the patient's chart
mounting
applications of electric current to the heart, directly ir indirectly, to alter a disturbance in cardia rhythm
countershocks
mechanism in the electrocardiograph that changes the voltage into a mechanical motioin or recording purposes
galvanometer
having or pertaining to a one-pole process
unipolar
the normal period in the cardiac cycle during which the myocardial fibers lengthen, the heart dilates and the cavities all fill with blood
diastole
one complete heartbeat
the cardia cycle
during an ultrasound procedure, this device picks up echoes and converts them to electrical energy
transducer
an area of tissue in an organ or a part that becomes necrotic after cessation of blood supply
infarction
amount, extent, size, abundance or fullness
amplitude
having equal electrical potentials, represented on the ECG as the baseline
isoelectric
the first three leads are
bipolar/standard leads
lead I records electrical activity between the
Left Arm AND Right Arm
lead II records electrical activity between the
Right Arm AND Left Leg
lead III records electrical activity between the
Left leg AND Left Arm
the next group of leads recorded after bipolar are
augemented/unipolar
augmented/unipolar leads are after the ________ and designated
bipolar, aVR, aVL, aVF
repolarization takes place while the heart muscle
relaxes
a type of chest electrode that consists of a disposable adhesive sensor is known as
precordial
one millivolt of cardia electrical activity will deflect the stylus exactly
10 mm high
a wandering baseline may be caused by
lotions, creams or oils on the patient's skin
where is SA node located
the upper part of the right atrium
SA node aka
body's natural pacemaker
what does the T wave represent
ventricular repolarization/ ventricular relaxation
baseline aka
iselectric
electrical activity that causes contraction is called
systole
electrical activity that causes relaxation is called
diastole
name the artifacts
somatic, ac interference, wandering baseline, interupted baseline
ex of somatic artifact
patient humming
ex of ac interference
crossed lead wires
ex of wandering baseline
lotions, oils or cream on patient's skin
interrupted baselin example is
detached lead wire
PAC
premature atrial contraction
PAC are experienced by _________
healthy individuals
ventricular fibrillation is seen in
patient's experiencing a MI or patient's with existing cardiac disease
ventricular fibrillation is __________ ___________
life threatening
ventricular tachycardia can lead to
death and fibrillation
a common disturbance, or arrhythmia seen on ECG's are
PVC, premature ventricular contractions
ischemia
lack of blood to an organ or part
ECG paper is
heat and pressure sensitive
the graph is a
tracing