EKG Flashcards
Depolarization
a change in electrical charge from negative to positive; causes the heart to contract
Repolarization
a change in electrical charge from positive back to negative; causes the heart muscle to relax
Sinoatrial Node
pacemaker of the heart, sets the timing of the heart’s contractions
Atrioventricular Node
slows down the impulse to allow the atria and ventricles to contract at different times
Isoelectric line
the straight line between the upward and downward movements
Positive wave
an inflection upward from the baseline
Negative wave
a deflection downward from the baseline
Segment
area between 2 waves
Interval
a wave and a segment together
Complex
several waves together
Normal Sinus Rhythm (NSR)
when the heart is functioning normally
P wave
atrial depolarization; contraction of the atria
QRS complex
ventricular depolarization; contraction of the ventricles
T wave
ventricular repolarization; relaxation of the ventricles
what leads do you use for extended monitoring
3 or 5 leads
Telemetry monitoring
monitors a patient’s EKG on an ongoing basis, 5 lead wires
Ambulatory monitoring
used when a pt is not hospitalized; Holter monitors are a common type
Event monitors
only record the heart’s electrical activity when the pt presses a button
Mobile cardiac telemetry
a type of ambulatory monitoring; automatically alerts a healthcare professional if an irregular heart rate or rhythm is detected
12-lead EKG
first test done when pt has chest pain or other S/S of heart problems, used for stress test
Leads I, II, and III
limb leads, bipolar leads
Leads aVR, aVL, and aVF
augmented limb leads; used same electrodes as leads I, II, and III but are unipolar leads
Leads V1, V2, V3, V4, V5, V6
precordial leads, chest leads; electrodes are placed in a line across the chest; unipolar leads
Dextrocardia
a rare heart condition that causes the heart ot point to the right side of the chest rather than the left side; chest electrodes must be placed over the heart on the right side of the chest
V4R placement
For pediatric pts V4R placement may be required due to their small chests
Posterior EKG
can help diagnose an inferior wall myocardial infarction; V4, V5, and V6 electrodes are placed on the back (now called V7, V8, and V9)
how to position a pregnant person for ekg
Pts over 6 months pregnant should not be placed in supine position for an EKG but instead tilted slightly to the left
Artifact
interference or distortion
Standard paper speed
25 mm/s
Gain
changes the sensitivity; how high or low the stylus moves
Standard gain
10 mm/mV
Calibration marker
a rectangle at the start of a strip; should be 5 mm wide by 10 mm tall
1 small box
0.1 mV, 0.04 secs
1 big box
0.5 mV, 0.2 secs
PR Segment
0.12 - 0.20 secs
QRS Complex
0.04 - 0.10 secs
QT Segment
0.36 - 0.44 secs
