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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


  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.


Right Atrial Hypertrophy. (ECG contributor: James V. Ritchie, MD.)


The P wave in lead II (an inferior lead) is greater than 2.5 mm in amplitude (double arrow).

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