Question

In the electrocardiogram (ECG) of humans, the electrical signature of atrial repolarization is masked by the ________

• A. P wave
• B. QRS complex
• C. T wave
• D. ST segment

Hint:

In an ECG, the P wave corresponds to atrial depolarization, the QRS complex corresponds to ventricular depolarization, and the T wave corresponds to ventricular repolarization.

Answer 1

The Correct Option is B

The electrocardiogram (ECG) represents the electrical activity of the heart. Each wave or complex in the ECG corresponds to specific electrical events in the heart.
Step 1: Atrial repolarization.
Atrial repolarization refers to the process by which the atria recover after contraction. This electrical signal is typically very small and occurs during the QRS complex. However, it is usually masked by the much larger electrical signals associated with ventricular depolarization, which generates the QRS complex.
Step 2: Understanding the QRS complex.
The QRS complex represents the depolarization of the ventricles, which is a much larger electrical signal than atrial repolarization. As a result, the electrical signature of atrial repolarization is hidden within the QRS complex.
Step 3: Conclusion.
The correct answer is (B), as the QRS complex masks the electrical signature of atrial repolarization.