Chapter 12 Cardiopulmonary Procedures Flashcards
P wave
Contraction of the Atria
Q wave
Contraction of the ventricles
T wave
aka ventricular repolarization, relaxation
QRS complex
the depolarization of the ventricles
P-R segment
the time between the end of atrial depolarization and the beginning of ventricular depolarization
S-T segment
from the end of ventricular depolarization to the beginning of repolarization of ventricles
Baseline
after T wave or U wave, period when entire heart returns to resting or polarized state
segment
time between two waves
-p-r segment, s-t segment
interval
length of a wave or length of wave with a segment
Q-T interval
time interval from the beginning of ventricular depolarization to the end of repolarization of the ventricles
P-R interval
time interval from the beginning of atrial depolarization to the beginning of ventricular depolarization
Normal standardization mark
10 mm high and 2 mm wide
electrocardiograph paper
thermosensitive paper divided into two sets of squares: small squares and large squares
-physician uses graph to measure waves, intervals and segments
electrocardiograph must be ________________ for every recording
standardized,
it is a quality control measure
if standardization mark is more or less than 10 mm high:
the machine must be adjusted, consult operating manual for adjustment information
Lead
a tracing of the electrical activity of the heart between two electrodes
- each lead provides an electrical photograph of heart’s activity from a different angle
- results in 12 photographs
Electrode (electrolyte)
a substance that facilitates the transmission of the heart’s electrical impulses
amplifier
device located in machine that amplifies the electrical impulses.
-electrical impulses given off by the heart are very small 0.0001 to 0.003 volt, therefore it must be amplified
galvanometer
changes amplified voltages into mechanical motion
The 10 lead wires:
- 4 limb lead wires (right and left arm, right and left leg)
- 6 chest lead wires
The right leg lead is used for ____________.
grounding of the machine,
not used for recording, serves as an electrical reference point
Electrodes _________ amplify the electrical impulses.
DO NOT
*note: the electrocardiograph amplifies
Lead I
records electrical current between right arm and left arm
Lead II
record electrical current between right arm and left leg
-shows hearts rhythm more clearly than other leads