Question

Which of the following correctly explains about ECG ?

• A. $P$ wave indicate atrial repolarisation
• B. QRS complex indicates ventricular repolarisation
• C. T-wave represents ventricular depolarisation
• D. P-wave indicates atrial repolarisation

Answer 1

None of the provided options are correct.

Answer 2

An Electrocardiogram (ECG) records the electrical activity of the heart. The standard ECG waveform consists of P wave, QRS complex, and T wave, each representing specific electrical events in the cardiac cycle:

1. P wave: This small upward deflection represents the atrial depolarization, which is the electrical activation of the atria leading to their contraction.

2. QRS complex: This rapid, large deflection represents the ventricular depolarization, which is the electrical activation of the ventricles leading to their contraction. The repolarization of the atria also occurs during this time, but it is masked by the larger QRS complex.

3. T wave: This upward deflection represents the ventricular repolarization, which is the electrical recovery (relaxation) of the ventricles.

Based on the standard physiological understanding of ECG waves, all the provided options are factually incorrect. Therefore, none of the options correctly explain about ECG.