Davis, T. P wave, Don't Forget the Bubbles, 2014. Available at:
Normally P amplitude < 3mm (tall P waves indicate RAH or ‘P pulmonale’).
Normal P wave duration < 0.09 seconds in children and 0.07 seconds in infants (wide P waves indicate LAH or ’P mitrale’).
A combination of tall and wide P waves occurs in combined atrial hypertophy.