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56 Cards in this Set

  • Front
  • Back
Define Electrocardiogram
the tracing made by an electrocardiograph; also: the procedure for producing an electrocardiogram
Define Contractility
the capability or quality of shrinking or contracting; especially: the power of muscle fibers of shortening into a more compact form
Define SA Node
a small mass of tissue that is made up of Purkinje fibers, ganglion cells, and nerve fibers, that is embedded in the musculature of the right atrium of higher vertebrates, and that originates the impulses stimulating the heartbeat
Define AV Node
small mass of tissue situated in wall of R atrium adjacent to septum between atria. passes impulses received from SA node to ventricles via bundle of His, and in some pathological states replaces the SA node as pacemaker of heart
Define Refractory period
the brief period immediately following the response especially of a muscle or nerve before it recovers the capacity to make a second response
Define Repolarization
restoration of the difference in charge between the inside and outside of the plasma membrane of a muscle fiber or cell following depolarization
Define Depolarization
loss of polarization; especially : loss of the difference in charge between the inside and outside of the plasma membrane of a muscle or nerve cell due to a change in permeability and migration of sodium ions to the interior
What does Lead I see?
RA (-) to LA (+) (Right Left, or lateral)
What does Lead II see?
RA (-) to LF (+) (Superior Inferior)
What does Lead III see?
LA (-) to LF (+) (Superior Inferior)
What does Lead aVR see?
RA (+) to [LA & LF] (-) (Leftward)
What does Lead aVF see?
LF (+) to [RA & LA] (-) (Inferior)
What does Lead aVL see?
LA (+) to [RA & LF] (-) (Rightward)
What do Leads V1, V2, V3 see?
(Posterior Anterior)
What do Leads V4, V5, V6 see?
(Right Left, or lateral
Define the part of the EKG tracing paper in terms of:
each small square running vertically represents 1 mm or 0.1 mV. The larger boxes are made up of five small squares and represent 5 mm or 0.5 mV
Define the part of the EKG tracing paper in terms of: Time
each small square running horizontally represents 0.04 seconds. Five of these small squares make up a larger box and represent 0.20 seconds. Five larger boxes = 1 second, 15 = 3 seconds
Be able to identify: Isoelectric line
a flat line indicating no electrical activity or activity too weak to be detected
Be able to identify: P wave
an upright, round waveform representing the initiation of the impulse in the SA node and its movement thru the atria (also conceptually represents contraction of the atria)
Be able to identify: PR segment
the isoelectric line following the P wave which represents the impulse traveling through the His-Purkinje system.
Be able to identify: PR interval
the distance from the beginning of the P wave to the beginning of the Q wave—represents depolarization of the heart from the SA node through the atria, AV node and His-Purkinje system. .12-.20 in duration.
Be able to identify: QRS complex
Consists of 3 parts: Q wave, R wave and S wave. Generally narrow & sharply pointed. Q wave is 1st downward deflection from baseline. R wave is 1st upward deflection after P wave; S wave is 1st negative deflection after R wave that extends below the baseline. Normally .06-.12 sec from beginning of Q to end of S or beginning of R. Represents movement of the electrical impulse thru ventricles and contraction
Be able to identify: ST segment
the pause following the QRS complex—ventricles are preparing to repolarize.
Be able to identify: Junction or J point
Where QRS meets ST is called the junction or J point.
Be able to identify: The T wave
follows the ST segment—represents ventricular Repolarization.
Be able to identify: QT interval:
The distance from the onset of QRS complex until end of T wave—represents ventricular depolarization & Repolarization. Varies according to age, sex & HR. Normally .36-.44 sec.
Be able to identify: Artifact
Markings on EKG that have no relationship to electrical activity of the heart; can be caused by pt movement, shivering, loose or improperly placed leads, worn out wires, malfunctioning machine or interference from improperly grounded equipment
Compare and contrast limb lead and precordial lead locations and waveform patterns
Limb leads (I, II, III, aVr, aVl and aVf) represent vertical cut thru middle of heart & view inferior, superior & lateral aspects of the heart. The precordial (chest) leads (V1, V2, V3, V4, V5, V6) represent horizontal plane/transverse cut thru middle of heart & provide anterior, lateral & posterior views
Review and be able to utilize the Five-Step Process of EKG tracing analysis
1. Determine the rate
2. Determine the regularity
3. Assess the P waves (uniform P wave preceding each QRS?)
d4. Assess the QRS (do they appear normal?)
5. Assess the PR intervals ( are they identifiable? Within normal limits? Constant in duration?)
Determine regularity by using the R-R intervals and P-P intervals
atrial regularity is determined by checking the distances between the upper or lower most points of the P waves to see if they are the same. Checking for differences between the R waves determines ventricular regularity
When the nerve impulses are in a polarized state the heart is at a
normal resting state
When the nerve impulses are depolarizing, the heart is _______
What is a normal rate for the SA node
What is a normal rate for the AV node
What is a normal rate for the Purkinje fibers
What areas of the heart are refered to as the supraventricular areas
SA, AV, Bundle of HIS
What areas of the heart are refered to as the ventricular areas
Bundle branches and purkinje fibers
How are rhythms named
named for the node generating the rhythm; sinus rhythm from SA node, A-fib from AV node, ventricular tachycardia from ventricles
What does chronotropic refer to?
affecting heart rate
What does inotropic refer to?
affecting contraction
What does dromotropic refer to?
affecting conduction
What is a rapid influx of positively charged ions from outside to inside a cell called
The impulse traveling thru the His_Purkinje system generates a _____ on the ECG
flat line following the P wave
The T wave represents?
ventricular repolarization
Cardiac output is equal to?
stroke volume multiplied by the heart rate
What is the reference point used to identify the changing electrical amplitude on the ECG called?
isoelectric line
Impulses that travel toward a positive electrode and away from a negative electrode are recorded as?
upward, upright or positive defelction where impulses traveling toward a negative electrode and away from a positive electrode are recorded as downward deflections
During the _______ initiation of the impulse in the SA node, its movement thru the atria and activation of the AV node occurs
P wave
The normal PR interval is how long in seconds
0.12 to 0.20
What lead is commonly used for continous ECG monitoring?
Lead II
What is the distance between 2 consecutive R waves called
R-R interval
The term used to describe sudden onset is
Patterned irregularity is
the irregularity repeating over and over in a cyclic fashion
Which of the following produces a totally irregular rhythm? Paroxysmal atrial tachycardia, Wenckebach, A-fib, Atrial flutter with varying conduction ratio?
When is a patterned irregular rhythm seen?
premature complexes occur every other (second) complex, every 3rd complex or every 4th complex