Which of the following represents ventricular depolarization in the heart's electrical conduction system?

• A. T wave
• B. P wave
• C. PR interval
• D. QRS complex

Answer: (D)

Verified step by step guidance

1. Understand the heart's electrical conduction system: The heart's electrical activity is represented by specific waves and intervals on an electrocardiogram (ECG). These include the P wave, QRS complex, T wave, and PR interval.
2. Identify the components of the ECG: The P wave represents atrial depolarization, the QRS complex represents ventricular depolarization, and the T wave represents ventricular repolarization. The PR interval is the time between the onset of the P wave and the start of the QRS complex, indicating the conduction time from the atria to the ventricles.
3. Focus on ventricular depolarization: Ventricular depolarization is the process by which the ventricles contract, and this is represented by the QRS complex on the ECG.
4. Differentiate between depolarization and repolarization: Depolarization refers to the electrical activation of the heart muscle, leading to contraction, while repolarization refers to the process of the heart muscle returning to its resting state.
5. Conclude with the correct representation: Based on the understanding of the ECG components, the QRS complex is the correct representation of ventricular depolarization in the heart's electrical conduction system.