EKG Flashcards
How many electrodes are placed on a 12 lead EKG
10
How much does one small square measure in the EKG paper
1 mm X 1 mm
What does the horizontal axis display
Time
What does the vertical axis display
gain or amplitude
How much does a small vertical square represent
0.1 mV
How much odes a small horizontal square represent
0.04 seconds
What is the normal speed the EKG paper should run
25 mm/sec
What is the normal gain or amplitude of the paper
10 mm or 1 mV
Which leads are bipolar
I, II, III
Which leads are unipolar
aVL, aVR, aVF
Which are the precordial leads
V1-V6
Placement of V1
right side of the sternum at the fourth intercostal space
Placement of V2
left side of the sternum at the fourth intercostal space
Placement of V3
Midway between V2 and V4
Placement of V4
Left side of the chest fifth intercostal space, midclavicular line
Placement of V5
Left side of the chest, fifth intercostal space, anterior axillary line
Placement of V6
Left side of the chest, fifth intercostal space, midaxillary line
What does the P wave represent
Atrial depolarization or contraction
What does the QRS complex represent
Ventricular depolarization or contraction
What does the T wave represent
Ventricular repolarization or relaxation
What does the U wave represent
Not always visible but represents a repolarization of the bundle of His and Purkinge fibers.
PR interval
Starts at the beginning of the P wave and ends at the beginning of the Q wave. Represents the time it takes from the beginning of atrial depolarization to the beginning of ventricular depolarization.
QT interval
Starts at the beginning of the Q wave and ends at the end of the T wave. Represents the time it takes from the beginning of ventricular depolarization to the end of ventricular repolarization.
ST segment
Starts at the end of the S wave and ends at the beginning of the T wave. Represents the time from the end of ventricular depolarization to the beginning of ventricular repolarization.
What is electrocardiography
The process of recording an electrocardiogram
Somatic tremor
Characterized by irregular spikes throughout the tracing and is related to muscle movement
AC interference
Characterized by regular spikes in the EKG tracing. It is related to poor grounding or external electricity interfering with the tracing.
Wandering baseline
Results from poor electrode connection. It can be associated with lotions, oils, powders on the skin, or expired electrodes.
Interrupted baseline
When there is a break in the tracing. It is usually related to a disconnected or broken lead wire.
