1 small box horizontal represents
.04 sec
1 small box vertical represents
1 mm
The normal paper speed should be set at
25 mm/sec
A normal calibration box should have the sensitivity and gain set at
1= 10mm tall = 10mm/mv
If you wanted to spread out the waves in a rapid rate, you should ________ the papers speed.
Increase (usually to 50mm/sec)
1500 method
calculate HR by counting the # of small boxes between the RR interval then dividing 1500 by that #; great for fast rhythms and very precise measurements
The 1500 small box method can be used to calculate heart rate for ________ rhythms
regular (ONLY)
The large box method can be used to calculate heart rate for ________ rhythms
regular (ONLY)
The sequence method can be used to calculate heart rate for _______ rhythms
regular (ONLY)
6 second method
count the number of QRS complexes in a 6 second period and multiply by 10
The 6 second method can be used to calculate heart rate for ______ rhythms
regular and irregular
electrocardiogram
a galvanometer that measures the electrical activity of heart
electrode
paper, plastic, or metal sensor placed on the patient's skin on a specific location that transmits info to the cable
lead
recorded tracing of the heart electricity from one or two electrodes that provides for a specific view of the heart
Einthoven's triangle
indicates correct limb lead placement for unipolar leads
unipolar leads
have only one "pole"; used as a reference point to create the "other end" of the lead system
bipolar leads
have two poles; one positive and one negative
Wilson's central terminal
a reference point created by the three limb leads (Einthoven's triangle); serves as a reference point for 6 / 12 leads and serves as the "zero" end for each of the 9 unipolar leads
causes of artifact in tracing
wandering baseline, seizure, trembling, dry/wet skin, cold patient, dry gel, cellphone interference
wandering baseline
often appears when electrodes are improperly placed on the torso; usually represents patient's respirations
eliminate: move limb leads to wrists and ankles
Dry skin artifact
if skin is too dry the electrodes and gel won't adhere well and won't produce a strong signal;
reduce: gently abrade skin and using tincture of benzoin to promote good adhesion
Cell phone interference
can cause lots of artifacts; may appear as flutter of P waves at a rate of 300/min;
Seizure activity artifact
will cause huge artifact problems on EKG: change in S deflection (goes further down)
3 lead EKG
usually used to CONTINUOUSLY monitor the patient's heart rhythm
White lead (3 lead)
right shoulder / clavicle area
Black lead ( 3-lead)
left shoulder/ clavicle area
Red Lead ( 3-lead)
left lower abdominal area
Green Lead ( 3-lead)
right lower abdominal area; serves as the GROUND LEAD in a 3-lead EKG
5 lead EKG
refers to the Holter monitor set up; has White, black, red, green, brown leads
White lead ( 5 lead)
right sternum/clavicle area
placing of V1 electrode
4th intercostal space, right sternal border
placing of V2 electrode
4th intercostal space, left sternal border
placing of V3 electrode
equidistant between V2 and V4
placing of V4 electrode
5th intercostal space, left midclavicular line
placing of V5 electrode
5th intercostal space, anterior axillary line
placing of V6 electrode
5th intercostal space, midaxillary line
Holter monitor
records EKG over 24 hours; used 5 leads
Holter monitor- ground lead placement
slightly right to below the sternum
why should you wear loose clothes for a holter monitor?
to reduce artifacct
when should the patient press the event button?
if they experience spontaneous symptoms unrelated to activity
the Holter monitor ______ get wet
cannot
only a _____ can replace loose leads on the Holter monitor
EKG technician
Tobacco products can be used up until
2-3 hours before a Holter monitor exam
Erectile dysfunction medications and caffeine should be avoided for _______ before a Holter monitor test
24 hours
site for pulse check during stress test
radial pulse
how often should you check BP during a stress test?
every 3 minutes
what symptoms indicate you should stop the stress test?
dizziness, decreased BP, ST elevation; then notify the physiccian
if the patient is hyperventilating during the stress test you should
check the respiratory rate
the target heart rate is generally calculated by
220 - pt age in years
you should stop a stress test when _____ or _____
the patient reaches target heart rate or becomes symptomatic
waveform
refers to movement away from isoelectric baseline with either positive or negative deflection
segment
line BETWEEN 2 waveforms
Interval
waveform PLUS a segment
complex
several waveforms consecutively
P wave represents
atrial depolarization
P wave should be less than _____ seconds (horizontal)
<.11 sec ( 3 small boxes)
P wave should be less than ______ mm (vertical)
< 2.5 mm (3 small boxes)
There is no wave for atrial repolarization because
it is obscured by the larger QRS complex
QRS complex represents
ventricular depolarization
QRS complex should be less than ____ seconds
< .1 sec (3 small boxes)
T wave represents
ventricular repolarization; slightly asymmetric
T wave should be less than ____ mm (vertical)
< 5mm ( 1 big box)
The U Wave, if present, represents
Purkinje repolarization
U wave, if present, should be less than _____ mm (vertical)
< 1.5 mm ( 2 small boxes)
A prominent (large) U wave is usually indicative of
hypokalemia (potassium deficiency)
PR segment
measured from end of the P wave to beginning of QRS; depolarization of AV node and its delay of the impulse
ST segment
represents time of ventricular contraction and beginning of repolarization in ventricles; most sensitive regarding cardiac ischemia
PR interval
P wave + PR segment;
normal length of PR interval
.12-.2 seconds ( 3-5 small boxes)
QT interval represents
total ventricular activity (depolarization and repolarization); normal duration depends on age and HR; measured from start of Q until end of T wave
RR interval
used to determine rhythm regularity and HR
causes of cardiac arrythmias
ectopic rhytms, sinus arrythmias, conduction blocks, pre-excitation syndrome
ectopic rhythm
electrical impulse originates from somwhere elese other than the SA node
conduction blocks
electrical impulses go down the usual pathway but encounter block and delays
Pre-excitation syndrome
the electrical impulses bypass the normal pathway and instead go down an accessory shortcut
Normal Sinus Rhythm
presence of P waves;
narrow QRS;
rate 60-100 BPM;
regular
sinus bradycardia
presence of P waves;
narrow QRS;
rate 40-60 BPm;
regular
sinus tachycardia
presence of P waves;
narrow QRS;
rate 100-160 BPM;
regular
sinus arrythmia
varying R-R interval, usually along with respirations;
has P waves;
narrow QRS;
rate usually 60-100 BPM;
IRREGULAR
sinus arrythmias are common in
children
atrial fibrillation
no P waves;
narrow QRS;
ventricular rate 60-100 BPM
irregularly irregular
atrial flutter
no P waves;
narrow QRS;
"SAWTOOTH WAVES"
atrial rate 240-320 BPM
regular
supraventricular tachycardia
maybe P waves;
narrow QRS;
ventricular rate 150-240 BPM
regular
Premature atrial complex
atrial depolarization that occurs early in the cardiac cycle;
how to name PAC rhythms
name underlying rhythm first then add PAC at the end
couplet
occurs in pairs of tair
bigeminy
occurs every other
trigeminy
occurs every 3rd
junctional rhythm
...