ECG placement Flashcards
What is an Electrocardiogram?
Records cardiac electrical currents by means of metal electrodes placed on the surface of the body.
TRUE OR FALSE: Patient should be treated immediately based on their ECG record
FALSE: Patients should be treated according to their symptoms, not merely their ECG.
Meaning of ECG or EKG
Electrocardiogram or electrokardiogram
What is an ECG
An ECG or EKG is a series of waves and deflections recording the heart’s electrical activity from a certain “view.”
What lead system gives you the complete view?
A 12-lead ECG paints a complete picture of the heart’s electrical activity by recording information through 12 different perspectives.
4 positional types of leads
- Right
- Anterior
- Lateral
- Inferior
What is the 12-lead ECG?
These 12 views are collected by placing electrodes or small, sticky patches on the chest (precordial), wrists, and ankles.
Clinical purposes
- To detect heart problems or blockages in the coronary arteries.
- To draw a graph of the electrical impulses moving through the heart
- To record heart rate and regularity of heart beats
- To diagnose a possible heart attack or other heart disorders
How many electrodes are there in 12 lead system?
10
Chest lead placements
V1 – 4TH ICS Right sternal border
V2 - 4TH ICS Left the sternal border
V3 – Midway between V2 and V4
V4 – 5th ICS Left MCL
V5 – 5th ICS Anterior Axillary line
V6 – 5th ICS Left Mid Axillary line
Limb placements
R – Right arm
L – Left arm
F – Foot (left leg)
N – Neutral (Right
foot)
3 Lead system (Cardiac Monitoring)
smoke over fire (black lead above
the red lead)
What is a lead?
A lead is a glimpse of the electrical activity of the heart from a particular angle. Put simply, a lead is like a perspective.
12 Lead groups
- Lead I
- Lead II
- Lead III
- Augmented Vector Right
(aVR) - Augmented Vector Left
(aVL) - Augmented vector foot
(aVF)
What are the standard leads (bipolar)
- Lead I - lateral wall
- Lead II - inferior wall
- Lead III - inferior wall
What are the augmented leads (unipolar)
aVR - no mans land
aVL - lateral wall
aVF - inferior wall
What are the chest leads (unipolar)
V1 - septal wall
V2 - septal wall
V3 - anterior wall
V4 - anterior wall
V5 - lateral wall
V6 - lateral wall
What leads are placed in the septal wall or to the septum?
V1, V2
What are leads placed in the anterior wall?
V3, V4
What leads are placed in inferior wall?
Lead II - inferior wall
Lead III - inferior wall
aVF (augmented vector foot)
What leads are placed in lateral wall?
Lead I - lateral wall
aVL - lateral wall (augmented vector left)
V5 - lateral wall
V6 - lateral wall
American Heart Association color and placement of leads
RA - white
LA - black
RL - green
LL - red
V1 - red
V2 - yellow
V3 - green
V4 - blue
V5 - orange
V6 - violet/purple
International Electrotechnical Commission
R - red
L - yellow
N - black
F - green
V1 - red
V2 - yellow
V3 - green
V4 - brown
V5 - black
V6 - violet/purple
An imaginary formation of three limb leads in a triangle used in electrocardiography, formed by the two shoulders and the pubis
Einthoven’s triangle
is ECG an invasive or non-invasive procedure?
Non-invasive
How should we position the patient during ECG placement
Semi-fowler’s position
What should we do as we place the pads?
- Chest skin should be dry, hairless, and oil-free.
- Electrodes should have full contact with the
patient’s skin. For better electrode adhesion and
oil-free skin, rub the area with an alcohol prep pad.
What pads should we put on first to the patient?
Limbs first and then chest leads
Do we need to remove the jewelry of the patient?
Yes. These must be removed before starting the procedure. Likewise, all personal belonging must be given after the procedure ends
What to document?
Document (Name, Age, Sex, Date and time
performed)
Precautions for ECG placing
- The recording equipment and other nearby electrical equipment should be properly grounded to prevent electrical interference.
- Double-check color codes and lead markings to be sure connectors match.
- Make sure that the electrodes are firmly attached, and reattached them if loose skin contact is suspended. Don’t use cables that are broken, frayed, or bare.
What is the conduction pathway of the heart?
- Pacing
- Conductive
- Non-conductive
- Contractile
What is Depolarization?
The electrical charge of a cell is altered by a shift of electrolytes on either side of the cell membrane. This change stimulates muscle fiber to contract.
What is Repolarization
Chemical pumps re-establish an internal negative charge as the cells return to their resting state.
Chemical pumps re-establish an internal negative charge as the cells return to their resting state.
Repolarization
The electrical charge of a cell is altered by a shift of electrolytes on either side of the cell membrane. This change stimulates muscle fiber to contract.
Depolarization
Impulse Conduction of the heart
- Sinoatrial node (SA)
- Atrio-ventricular node (AV)
- Bundle of His
- Bundle branches
- Purkinje fibers
Depolarization:___________
Dsicharge
Repolarization:____________
Recharge
Normal duration of P wave
P wave normal duration is 0.06 to 0.12 seconds
Characteristics of P wave
Concave and small
Clinical Significance: Atrial depolarization
P wave
Clinical Significance of P wave
Clinical Significance: Atrial depolarization
normal duration of PR interval
PR interval normal duration is 0.12 to 0.20 seconds
Characteristics of PR interval
Characteristics: Period from the start of the P wave to the beginning of the
QRS complex
Clinical significance of PR interval
Clinical Significance: AV conduction time
normal duration of QRS complex
QRS Complex normal duration is 0.06-0.12 seconds
characteristics of QRS complex
Characteristics: R waves are deflected positively and the Q and S waves
are negative
Clinical significance of QRS complex
Clinical Significance: Ventricular depolarization
Clinical Significance: Ventricular depolarization
QRS complex
Characteristics: R waves are deflected positively and the Q and S waves
are negative
QRS complex
Normally not depressed more than 0.5 mm and not elevated no more than 1 mm
ST Segment
Characteristics: Isoelectric
ST Segment
Characteristic of ST segment
Isoelectric
Clinical Significance: Early ventricular repolarization
ST Segment
Clinical Significance of ST segment
Clinical Significance: Early ventricular repolarization
Normal values are between 0.30 and 0.44 (0.45 for women) seconds
QT segment
Clinical Significance: Ventricular depolarization and repolarization
QT segment
Characteristics: Rounded and asymmetrical
T wave
characteristics of T wave
Characteristics: Rounded and asymmetrical
Clinical Significance: Ventricular repolarization
T wave
clinical significance of T wave
Clinical Significance: Ventricular repolarization
three stages of a single heartbeat
1.Atrial depolarization
2.Ventricular depolarization
3.Atrial and ventricular repolarization
