Which interval shows the time needed for the ventricles to contract and recover?

Which interval shows the time needed for the ventricles to contract and recover?

• A. QT Interval
• B. QRS Complex
• C. Pacemaker
• D. Rhythm Strip

Answer: (A)

The ventricular cycle on the ECG is reflected by the QT interval. It starts with the beginning of ventricular depolarization (the start of the Q wave, or the R wave if there’s no Q) and ends at the end of ventricular repolarization (the T wave). This interval thus includes the time the ventricles are contracting and then recovering, so it best represents the total time of ventricular electrical activity. The QRS complex only shows ventricular depolarization (contraction), not recovery. A pacemaker is a device, not a measurement, and a rhythm strip is just a type of tracing, not a specific interval.

The ventricular cycle on the ECG is reflected by the QT interval. It starts with the beginning of ventricular depolarization (the start of the Q wave, or the R wave if there’s no Q) and ends at the end of ventricular repolarization (the T wave). This interval thus includes the time the ventricles are contracting and then recovering, so it best represents the total time of ventricular electrical activity. The QRS complex only shows ventricular depolarization (contraction), not recovery. A pacemaker is a device, not a measurement, and a rhythm strip is just a type of tracing, not a specific interval.