 
<translate> Ajụjụ. Ihe e dere na ya: Ebili mmiri P dị na ECG na-anọchi anya nkwụsịtụ nke akwara obi, nke na-eme ka akwara obi na-ebelata, ma ọ bụ akwara obi na-ebelata.  Ajụjụ: ihe p-wave phase nke electrocardiogram (ecg) na-anọchi anya ya? Azịza ya bụ na ọ na- eme ka obi ghara ịdị n" otu, nke na- eme ka obi na- agbachi agbachi, ma ọ bụ na- eme ka obi na- agbachi agbachi Olee ihe e kwuru nke na-egosi na azịza ya bụ eziokwu? <eng> Question. Context: The P wave in the ECG represents atrial depolarization, which results in atrial contraction, or atrial systole.

Question: the p-wave phase of an electrocardiogram (ecg) represents?
Answer. atrial depolarization , which results in atrial contraction , or atrial systole
What step-by-step reasoning justifies that answer? 