Right atrial enlargement


According to echocardiography mean RA area is approx. 14 cm2, considered enlarged when >18 cm2.


  • raised right ventricular pressures
  • pulmonary arterial hypertension
  • cor pulmonale
  • valvular disease
  • tricuspid regurgitation
  • Ebstein anomaly
  • atrial septal defect (ASD)
  • atrial fibrillation (AF)
  • dilated cardiomyopathy

ECG findings suggestive of right atrial enlargement:

  • P pulmonale: P wave amplitude >2.5mm in inferior leads (II, III, AVF) or >1.5mm in V1/V2
  • P wave axis shifted rightward >70°

P pulmonale

ECG 1 Patient with pulmonary artery hypertension - RBBB, right axis deviation (dominant negative deflection in leads I and aVL), R wave > 7mm in V1, ST depressions in V1-V3, P pulmonale

ECG 2 P pulmonale in a patient with right atrial enlargement 


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  2. Lan NSH, Massam BD, Kulkarni SS, Lang CC. Pulmonary Arterial Hypertension: Pathophysiology and Treatment. Diseases. 2018;6(2):38. Published 2018 May 16. doi:10.3390/diseases6020038
  3. Henkens IR, Scherptong RW, van Kralingen KW, Said SA, Vliegen HW. Pulmonary hypertension: the role of the electrocardiogram. Neth Heart J. 2008;16(7-8):250-254. doi:10.1007/BF03086156
  4. Barto, Donna MA, RN, CCRN Recognizing pulmonary hypertension on the ECG, Nursing Critical Care: March 2011 - Volume 6 - Issue 2 - p 11-13 doi: 10.1097/01.CCN.0000394497.97148.d7