According to echocardiography mean RA area is approx. 14 cm2, considered enlarged when >18 cm2.
Causes
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
References
Ryan JJ, Thenappan T, Luo N, et al. The WHO classification of pulmonary hypertension: A case-based imaging compendium. Pulm Circ. 2012;2(1):107-121. doi:10.4103/2045-8932.94843
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
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
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
