The T wave corresponds to which cardiac electrical event?

The T wave corresponds to which cardiac electrical event?

• A. Ventricular repolarization
• B. Atrial depolarization
• C. Ventricular depolarization
• D. Atrial repolarization

Answer: (A)

The T wave shows ventricular repolarization—the ventricles resetting back to their resting electrical state after they have contracted. After the ventricles depolarize and contract (the QRS complex), the heart muscle cells must return to their baseline membrane potential. This recovery phase, driven by ions moving back to their resting positions, creates the T wave on the ECG. For context, the atrial depolarization that starts a heartbeat is the P wave, and ventricular depolarization—the signal that triggers contraction—is the QRS complex. Atrial repolarization does occur, but it is hidden within the large QRS complex and not seen as a separate deflection.

The T wave shows ventricular repolarization—the ventricles resetting back to their resting electrical state after they have contracted. After the ventricles depolarize and contract (the QRS complex), the heart muscle cells must return to their baseline membrane potential. This recovery phase, driven by ions moving back to their resting positions, creates the T wave on the ECG. For context, the atrial depolarization that starts a heartbeat is the P wave, and ventricular depolarization—the signal that triggers contraction—is the QRS complex. Atrial repolarization does occur, but it is hidden within the large QRS complex and not seen as a separate deflection.