23-41: Right Atrial Hypertrophy

ECG Findings

• Increased amplitude of P wave without affecting duration (as commonly seen with left atrial abnormalities)

• Peaked P waves (> 2.5 mm) in leads II, III, aVF

• P-wave upward deflection > 1.5 mm in lead V₁ or V₂

Pearls

1. Normal P-wave morphology has amplitude of < 2.5 mV (2.5 small vertical boxes) and duration (width) of < 120 ms (three small boxes).

2. The right atrium depolarizes before the left atrium and therefore has the most effect on the 1st portion of the P wave.

3. Right atrial enlargement is often associated with RVH, COPD, some congenital heart diseases, and pulmonary hypertension, and may be seen transiently with pulmonary embolus.