Electocardiogram (ECG) Flashcards
Electrocardiogram
ECG or EKG
Graphic representation of the electrical activity that passes through the heart
What level does the electrical activity of the heart begin?
The electrical activity of the heart begins at the cellular level. Then follows the conductive pathway, bringing about the cardiac cycle which results in the heart pumping blood throughout the body.
Cardiac Polarity
Electrical status of cardiac muscle cells
Polarization
Resting cardiac muscle cells
Depolarization
Charged and contracting cardiac muscle cells
Repolarization
Recovering cardiac muscle cells and returning to equilibrium
What is the cardiac cycle?
The pumping of the heart in rhythmic cycle of contraction and relaxation.
(“Lub-dub” sound)
Adult heart rate
60-100 Bpm
ECG complex is what?
A full cardiac electrical cycle represented by PQRST waves working together as a complex
P wave is…
And upward curve resenting atrial contraction used to measure the arterial rate
Q wave is…
A downward deflection after the P wave
R wave is…
A large upward spike after the Q wave
S wave is…
A downward deflection after the R wave
T wave is…
And upward curve after the S wave. Representing the repolarization and resting of the ventricle
U wave is …
A small upward curve sometimes following the T wave. Representing slow repolarization a return to resting
What is the QRS complex?
The QRS waves representing contraction of the ventricles
What is the PR interval?
The P-wave in the line connecting it to the QRS complex. Representing the time the electrical impulse travels from the sinoatrial (SA) node to the atrioventricular (AV) node.
What is the QT interval?
The QRST waves were presenting a full cardiac electrical cycle
What is the ST segment?
A slight upward line connecting the QRS waves to the T wave and representing the time between contraction of the ventricles and relaxation or recovery
4 types of ECG’s:
1) Single-lead
2) 12 lead
3) Telemetry
4) Interpretive
What is a single lead ECG?
Info recorded from one view of the heart.
What’s a 12 lead ECG?
Info recorded from 10 electrodes.
Representing 12 views of the ❤️from 12 angles.
What is a telemetry ECG?
A single lead or 12 lead transmitted by radio, electronic or telephone waves to another site for monitoring or reading
Interpretive ECG is a…
Computerized ECG programed to analyze data & produce a printed interpretation.
Placement of electrodes
10 sensors
•Chest electrodes (6)
{V1-V6}
•Limb electrodes (4)
{RA & RL}
{LA & LL}
Which limb electrode is the ground on an ECG?
RL - Right Leg
V1 placement
4th intercostal space @ right margin of sternum.
V2 placement
4th intercostal space @ left margin of the sternum.
V3 placement
Midway between V2 & V4
V4 placement
5th intercostal space @ left midclavicular line
V5 placement
Placed midway between V4 & V6
V6 placement
5th intercostal space @ the left midaxillary line.
