ECG 1 Flashcards
What is an electrocardiogram a recording of?
Voltage in respect of time
Where is the ground electrode located on a patient?
Right leg
Define depolarization
contraction
What are leads I, II, III?
Standard or bipolar
Where must limb sensors be placed in order to obtain an accurate ECG?
Upper arms and lower legs
What are the devices that attach to the skin called?
Sensors or electrodes
What setting controls the amount of voltage represented on the tracing?
Amplitude
What does vertical deflection from the baseline on the ECG represent?
Voltage
What is the reference mark to determine amplitude?
Standardization mark
What are aVR, aVL, aVF known as?
Augmented Leads
What is the SA Node?
It initiates and regulates heartbeat
List the characteristics of cardiac muscle
- It’s striated
- Has dark Z lines
- Can contract without being triggered by nerve impulse
What valve is located between the left atrium and left ventricle?
Bicuspid valve
What are the right and left side of the heart separated by?
Septa
Define Parietal Pericardium
The loose fitting sac that covers the heart
What is the foramen ovale and what is it called after birth?
- A depression in the inter-atrial septum
- Fossa Ovalis
List the layers of the heart and their function
- Epicardium (outer layer)
- Myocardium (middle layer)
- Endocardium (inner layer)
Where is deoxygenated blood pumped into?
Pulmonary veins
Define stroke volume
The volume of blood pumped by each ventricle in 1 beat
Define cardiac output
The volume of blood pumped by each ventricle in 1 minute
What part of the heart receives oxygenated blood from the pulmonary veins?
Right atrium
Where does the right ventricle pump the blood into?
Pulmonary arteries
List the 4 chambers of the heart
Right atrium
Left atrium
Right ventricle
Left ventricle
Name the heart valves
Tricuspid
Bicuspid
Pulmonary semilunar valve
Aortic
Define polarization
where electrical charges are balanced
Define Re-Polarization
Re-Contraction
What is the blood circulation pattern?
The blood enters the right atrium from the superior and inferior vena cava
- Goes through tricuspid valve
- Into right ventricle
- Through pulmonary semilunar valve
- Through pulmonary artery
- Into the lungs
- Into pulmonary veins
- Into left atrium
- Through bicuspid valve
- Into left ventricle
- Through aortic valve
- Into aorta
What is standard calibration of ECG machine?
10 mm per 1 millivolt
How fast does ECG paper trace?
25 mm per second
What is the function of aVR?
voltage difference between right arm and central point between left arm and leg
What is the function of aVF?
Voltage difference between left leg to central point between right and left arm
What is the function of aVL
voltage difference between left arm to central point between the right arm and left leg
List the leads and their location
- V1: 4th intercostal space at right margin of sternum
- V2: 4th intercostal space on left side of sternum
- V3: midway between position 2 and 4
- V4: 5th intercostal space at junction of left midclavicular line
- V5: Horizontal level of position 4 at left anterior axillary line
- V6: Horizontal level of position 4 at left midaxillary line
Define P Wave
atrial depolarization
Define QRS Complex
ventricular depolarization
Define T Wave
ventricular repolarization
What is P-R Segment?
end of P Wave to the beginning of QRS Complex
What is S-T Segment?
end of QRS Complex to beginning of T Wave
What is P-R Interval?
Beginning of P Wave to the beginning of QRS Complex
What is Q-T Interval?
Beginning of QRS Complex to the end of T Wave
What is an artifact?
Interference of ECG results
List ECG artifacts
Muscle Artifact (inconsistent)
Wandering Baseline
Alternating Current Artifact (consistent)
Interrupted Baseline
What is the Holter Monitor Used for?
- To detect arrhythmia
- To assess the function of a pacemaker
- To assess medication efficacy
- To find the cause of unexplained fainting
Color and placement of Holter Monitor electrodes
White: right side under clavicle
Brown: left side under clavicle
Black: left side, fourth intercostal space
Red: left side, fifth intercostal space, midaxillary line
Green: right side, any flat surface, usually opposite red electrode
