Rhythm InterpretationQuestion 30 of 100
What does the QT interval measure on an EKG tracing?
a.The time for the atria to depolarize and repolarize
b.The total time for ventricular depolarization and repolarization
c.The delay of the impulse at the AV node
d.The time between two consecutive R waves
Explanation
The QT interval is measured from the start of the QRS complex to the end of the T wave and represents the full cycle of ventricular depolarization and recovery; it normally occupies less than half of the R-R interval and generally measures under about 0.44 second at normal rates. Atrial activity is represented by the P wave. The AV nodal delay lies inside the PR interval, and the R-R interval measures rate and regularity.
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