Which wave on the electrocardiogram (ECG) represents ventricular depolarization?

• A. T wave
• B. QRS complex
• C. U wave
• D. P wave

Answer: (B)

Verified step by step guidance

1. Understand the components of an electrocardiogram (ECG): An ECG is a graphical representation of the electrical activity of the heart. It consists of several waves, each representing different phases of the cardiac cycle.
2. Identify the waves on an ECG: The main waves are the P wave, QRS complex, T wave, and sometimes a U wave. Each wave corresponds to specific electrical events in the heart.
3. Recognize the P wave: The P wave represents atrial depolarization, which is the electrical activity associated with the contraction of the atria.
4. Understand the QRS complex: The QRS complex represents ventricular depolarization, which is the electrical activity associated with the contraction of the ventricles. This is typically the largest wave on the ECG due to the larger muscle mass of the ventricles compared to the atria.
5. Differentiate the T wave: The T wave represents ventricular repolarization, which is the process of the ventricles returning to their resting state after contraction. The U wave, if present, follows the T wave and is less commonly discussed.