What does the T wave represent in an ECG reading?

• A. Atrial contraction
• B. Ventricular contraction
• C. Ventricular repolarization or recovery
• D. Electrical activity of the atria

Answer: (C)

The T wave in an ECG reading represents the process of ventricular repolarization, which is crucial for the heart's electrical cycle. After the ventricles contract and pump blood out of the heart (this is represented by the QRS complex), they must return to their resting state electrically. The T wave reflects this recovery phase, indicating that the ventricles are repolarizing and preparing for the next cycle of contraction. This phase is essential for the heart's ability to function effectively, as it ensures the ventricles are ready to contract again in a coordinated manner. Understanding the significance of the T wave helps in diagnosing various cardiac conditions, as abnormalities in this wave can indicate issues such as ischemia or electrolyte imbalances.