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28 Cards in this Set
- Front
- Back
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The P Wave location, amplitude, duration, configuration, deflection
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Location:Precedes QRS
Amplitude: 2-3 mm high Duration: 0.06-0.12 Config/Deflect: rounded & upright, positive |
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The P Wave Signigicance
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Represents atrial depolarization
When normal, assume impulse originated in the SA node (sinus rythym) |
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Abnormal P Waves
Peaked, notched, or enlarged |
May represent atrial hypertrophy or enlargement associated with COPD , pulmonary emboli, valvular diseae, or heart failure.
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Abnormal P Waves
Inverted P Waves |
May signify retrograde or reverse conduction from the AV junction toward the atria.
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Abnormal P Waves
Varying P Waves |
The impulse may be coming from different sites, as with a wandering pacemaker, irritable atrial tissue, or damage near the SA node
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Abnormal P Waves
Absent P Waves |
May signify conduction by a route other than the SA node, as with a junctional or atrial fibrillation rhythm
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PR Interval
Location, Duration |
Location-from the beginning of the P wave to the beginning of the QRS complex
Duration-0.12-0.20 sec |
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PR Interval Representation
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Tracks the atrial impulse from the atria thru the AV node, bundle of His, and right and left bundle branches. Key is its duration
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Abnormal PRI
Shortened |
Less than 0.12 sec
Indicate that the impulse originated somewhere other than the SA node. Associated with junctional arrhythmias and preexcitation syndromes. |
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Abnormal PRI
Lengthened |
Greater than 0.20 seconds
May represent a conduction delay thru the atria or AV junction due to digoxin toxicity or heart block-slowing related to ischemia or conduction tissue disease |
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QRS Complex Representation
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Follows the P wave and represents depolarization of the ventricles
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QRS Location, Amplitude, Duration,
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Location-follows the PRI
Amplitude-5-30 mm but differs for each lead Duration-0.06-0.12 sec (measured from the beginning of the Q wave to the end of the S wave or from the beginning of the R wave if the Q wave is absent) |
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Abnormal QRS
Variations |
Deep wide Q waves may represent MI
Notched R waves may signify a BBB Widened QRS may signify a ventricular conduction delay Missing QRS may indicate an AV block or ventricualr standstill |
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ST Segment Representation
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Represents the end of ventricular conduction or depolarization and the beginning of ventricular recovery or repolarization.
Monitoring can help detect ischemia or injury before infarction develops. |
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ST Segment Location and Deflection
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Location-extends from the S wave to the beginning of the T wave
Deflection-Usually isoelectric-may vary from -0.5-1 mm |
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Abnormal ST Segment
Depression |
0.5mm or more below baseline
May indicate myocardial ischemia or digoxin toxicity |
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Abnormal ST Segment
Elevation |
1mm or more above baseline
May indicate myocardial injury |
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T Wave Representation
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Represents ventricular recovery or repolarization
Also represents the relative refractory period |
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T Wave Location and Configuration
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Location-follows the S wave
Configuration-typically round and smooth |
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Abnormal T waves
Bumpy T's |
Because T's represent the relative refractory period, bumps may indicate that a P wave is hidden in it
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Abnormal T Waves
Tall, Peaked, Tented |
Myocardial injury OR
Hyperkalemia |
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Abnormal T Waves
Inverted |
May represent myocardial ischemia
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Abnormal T Waves
Heavily notched or pointed |
In an adult, may represent pericarditis
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QT Interval Representation
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Represents the time needed for ventricular depolarization-repolarization cycle
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Abnormal QT
Prolonged |
Represents a longer relative refractory period and increases the risk of a life threatening arrhythmia known as torsades de points
Also associated with Class 1 Anti-arrhythmics |
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Abnormal QT
Shortened |
May result from digoxin toxicity or hypercalcemia
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U Wave Representation
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Represents the recovery period of the Purkinje or ventricular conduction fibers
NOT present on every strip |
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Abnormal U Wave
Prominent |
Hypercalcemia
Hypokalemia Digoxin toxicity |
