Question

P-wave is mainly caused by the

• A. Systole of atria
• B. Diastole of atria
• C. Systole of the left ventricle
• D. Systole of the right ventricle

Answer 1

The correct option is A Systole of atria

In an electrocardiogram (ECG), the P-wave indicates the activation of the Sino-atrial node. The P-wave is caused mainly by a change of a flow rate of arterial blood flow. The P-wave represents the electrical excitation (or depolarization) of the atria, which leads to the contraction of both the atria. During this phase, the impulse of contraction is generated by the SA node, causing atrial depolarization.

Thus, the correct answer is option A.