During the QRS complex, which statement is true?

During the QRS complex, which statement is true?

• A. It represents atrial depolarization
• B. It represents ventricular depolarization
• C. It represents atrial repolarization
• D. It represents ventricular repolarization

Answer: (B)

The QRS complex reflects ventricular depolarization. This is when the electrical impulse rapidly travels through the ventricles, causing their muscle cells to contract. The P wave that precedes it represents atrial depolarization, while the T wave that follows shows ventricular repolarization. Atrial repolarization occurs during the QRS complex but is usually hidden by the much larger ventricular depolarization, so it isn’t seen as a separate deflection. Therefore, the true statement is that the QRS complex represents ventricular depolarization.

The QRS complex reflects ventricular depolarization. This is when the electrical impulse rapidly travels through the ventricles, causing their muscle cells to contract. The P wave that precedes it represents atrial depolarization, while the T wave that follows shows ventricular repolarization. Atrial repolarization occurs during the QRS complex but is usually hidden by the much larger ventricular depolarization, so it isn’t seen as a separate deflection. Therefore, the true statement is that the QRS complex represents ventricular depolarization.