What does the QRS wave of the electrocardiogram (ECG) represent?

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

Answer: (A)

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 QRS complex: The QRS complex is one of the most prominent features on an ECG. It typically follows the P wave and precedes the T wave.
3. Recognize the physiological process: The QRS complex represents the depolarization of the ventricles. This is the process where the ventricles prepare to contract and pump blood out of the heart.
4. Differentiate between depolarization and repolarization: Depolarization is the electrical activation of the heart muscle, leading to contraction, while repolarization is the process of the heart muscle returning to its resting state.
5. Relate the QRS complex to the options given: Among the options provided, the QRS wave corresponds to ventricular depolarization, as it signifies the electrical activity that leads to the contraction of the ventricles.