Q. What does a P wave on an EKG signify?
A. The P wave represents atrial depolarization. It should have an upward direction in leads I and II but inverted in aVR. You can detect right atrial enlargement by a taller than normal P wave in lead II, and left atrial enlargement by a notched P wave in lead II. It is normal for the P wave to be biphasic in lead V1.
Source: LITFL
















