Often, the P wave is inverted in lead II, if it can be seen at all. A pacemaker may be needed to relieve symptoms when no reversible cause — i.e. AV blocking medications or electrolyte ...

This results in an inverted P wave in lead II (normally upright in sinus rhythm) and an upright P wave in aVR (normally inverted in sinus rhythm). Depending on the exact location of the pacemaker ...