Right Atrial Enlargement: ECG and Chest X-Ray : Dr. Akif Baig

Greater RA mass and size generate greater electrical forces early during atrial activation, producing taller P waves in limb leads and increasing the initial P wave deflection in leads such as lead V1 that face the right heart
Because RA activation occurs early during the P wave, P wave duration is not prolonged, in contrast to the pattern with LA enlargement
Downward displacement of the heart may be responsible for the increase in P-terminal force and tall P waves in patients with emphysema