Right Atrial Enlargement on Electrocardiogram in Previously Healthy Young Patients.

OBJECTIVES: To assess whether right atrial enlargement (RAE) on electrocardiogram (ECG) correlates with true RAE on echocardiogram in previously healthy young patients and to understand which patients with RAE on ECG may warrant additional testing. STUDY DESIGN: A single-center, retrospective review of previously healthy young patients with (1) ECGs that were read as RAE by a pediatric cardiologist and (2) echocardiograms obtained within 90 days of the ECG. ECGs were reviewed to confirm RAE and determine which leads met criteria. The echocardiograms were then reviewed and RA measurements with z scores obtained. A z score >2 was considered positive for RAE on echocardiogram. RESULTS: In total, 162 patients with median age 10.8 years were included in the study. A total of 23 patients had true RAE on echocardiogram, giving a positive predictive value (PPV) of 14%. In patients <1 year of age, the PPV increased to 35%. In patients older than 1 year, the PPV was low at 7%. Patients with true RAE were more likely to meet criteria for RAE in the anterior precordial leads (V1-V3) (48% vs 5%, P < .001) and meet criteria for right ventricular hypertrophy (22% vs 6%, P = .023). CONCLUSION: Our findings show that RAE on ECG has a low PPV for RAE on echocardiogram in previously healthy young patients. The highest yield for RAE on echocardiogram was observed in patients who were <1 year of age, had RAE in the anterior precordial leads, or displayed right ventricular hypertrophy on ECG.