57 terms

EKG exam

is an amplifier, a sensor, and a recorder
Electrocariograph is a measurement of
Voltage (vertical) in respect to time (horizontal)
1mm or 0.04 seconds
represents each smaller square on the EKG paper
normal speed for an EKG tracing
What happens when the EKG is recorded at a faster speed
it will stretch
what happens if the EKG paper is to slow
causes it to compress
what does the sensitivity key control
how much gain of amplification the ECG will have
Normal sensitivity setting on the EKG
IF sensitivity is turned down to 1/2
the EKG will record all cardiac action at half its normal amplitude, deflections appear half as big, with waves half as tall
If sensitivity is increased to 2`
the EKG will record cardiac action at twice its normal amplitude, waves twice as tall
Each EKG tracing should begin with
A calibration check
how is a calibration check done
automatically by the EKG, and the mark it produces is called a standardization mark
The universal standard for the calibration check
1 millivolt of electrical activity should deflect the stylus exactly 10mm high
Diagnostic EKG is determined by
comparison between tracings of cardiac electrical activity
Discharge of electrical energy in the heart that typically causes contraction of the heart muscle cells
term for the heart muschle cells electrically "resetting" itself or returning to its polarized state.
Lead I records
electrical activity between LA and RA
Lead II records
electrical activity between LL and RA
Lead III records
electrical activity between LL and LA
aVR records
electrical activity between RA and halfway between LA and LL
aVL records
electrical activity between LA and halfway between RA and LL
electrical activity between LL and halfway between RA and LA
how can we determine the probable location of artifact voltages
by finding the commonalities within the views that record them
EKG records
cardiac voltage, and artifact voltages
4 artifacts
Somatic or muscle artifact AKA somatic tremor, AC interference (alternating current), wandering baseline, interrupted basline
somatic/muscle artifact voltages demonstrates
typically an erratic amplitude and frequency
cause of somatic artifact
pt movement, talking, or shaking due to cold or apprehension, vibration within the environment
AC interference demonstrates
typically a consistent amplitude and frequency
Cause of AC interference
improper grounding, presence of an electrical field, "cross talking" from crossed lead wires
Causes of wandering baseline
loose sensors, oily skin or lotion on skin, corroded sensors, or improper electorlyte
contductor of electrical impluses
why is electrolyte used to conduct electrical impulses
skin is a poor conductor
greatest disadvantage of using metal electrodes
cleaning the electrolyte paste off
how to obtain a good quality EKG
pt comfortable and relaxed, warm, pillow under head, adequate support for arms and legs
Chest lead
AKA precordial lead
Chest lead requires what
placement precise and proper positioning in order to obtain the most accurate results
V1 placed
at the 4th intercostal space on the right margin of the sternum
V2 placed
at the 4th intercostal space on the left margin of the sternum
V4 placed
at the 5th intercostal space on the left midclavicularline
V3 placed
halfway between V2 and V4
V5 placed
on the same horizontal level as V4, on the left anterior axillary line
V6 placed
on the same horizontal level as V4, on the midaxillary line
limb leads placed
RA, LA, RL, and LL
What limb lead is used as a ground
RL, electrical reference point only
Isoelectric line
AKA baseline, relatively straight line that is recorded in the absence of electrical activity
terms for variations from the baseline
P Wave
is the first deflection demostrated in a normal sinus rhythm
P wave represents
atrial depolarization
P wave followed by
the QRS complex
QRS Complex represents
ventricular depolarization
What follows QRS complex
T wave
T wave represents
cardiac repolarization, especially of the ventricles
What may follow the T wave
u wave
is the u wave normal
yes a normal occurrence but rare
standard limb leads
Leads I, II, III, they are bipolar and typically demonstrate upward, or positive deflections
aurgmented limb leads
aVR, aVF, aVL and are unipolar. They typically demonstrate downward of negative deflections
Chest leads
record activity froma central point within the heart looking out at one of 6 designated leads called V or C leads they record in sequence from right (V1) to left (V6)