P wave

Which ECG changes are typical for isolated chronic left atrial pressure or volume overload?

1. Prolongation of the P wave to more than the normal 100 ms

2. In leads I and II, the P wave has two peaks, and in leads III, V1, and V2 it is biphasic, which means that it is first positive, then negative.

3. The PQ interval is shortened due to the extension of the P wave.