ANATOMY

Detailed explanation-1: -The P wave represents the electrical depolarization of the atria. In a healthy person, this originates at the sinoatrial node (SA node) and disperses into both left and right atria.

Detailed explanation-2: -P wave in ECG deflection represents atrial depolarization. Atrial repolarization occurs during ventricular depolarization and is obscured.

Detailed explanation-3: -The P wave represents the depolarization of the left and right atrium and also corresponds to atrial contraction. Strictly speaking, the atria contract a split second after the P wave begins. Because it is so small, atrial repolarization is usually not visible on ECG.

Detailed explanation-4: -P wave in the ECG represents the electrical excitation of the atria (depolarisation) which causes contraction of both the atria.

Detailed explanation-5: -His labeling of the primitive tracing was then mixed: A and B, the first letters of the alphabet, were used to indicate ventricular events, and P, from near the middle of the alphabet, was used to indicate atrial events.