EKG P Wave Definition, duration, shape

P Wave Definition

The P wave represents atrial depolarization. In a normal EKG, the P-wave precedes the QRS complex. It looks like a small bump upwards from the baseline. The amplitude is normally 0.05 to 0.25mV (0.5 to 2.5 small boxes). Normal duration is 0.06-0.11 seconds (1.5 to 2.75 small boxes). The shape of a P-wave is usually smooth and rounded.

P-wave questions:

  • Are they present?

  • Do they occur regularly?

  • Is there one P-wave for each QRS complex?

  • Are the P-Waves smooth, rounded, and upright?

  • Do all P-Waves have similar shapes?

P Wave illustration

second image