Left atrial enlargement

Left atrial enlargement (LAE) is a consequence of increased left atrial pressure or volume over a longer period of time. This may be due to left-to-right shunt, hypertension, mitral regurgitation, or mitral stenosis.

It is asymptomatic in itself, but the presence LAE increases the risk of atrial fibrillation, stroke, and HFpEF.

Diagnosis and evaluation

Echocardiography is the best modality for measuring the size of the left atrium. ECG may show:

• Wide P wave > 0.11 s
• "P mitrale" - a notched or bifid P wave
• P wave axis < 30 degrees

Chest radiography may show superior displacement of the left main bronchus, best visible on the lateral radiograph as the "walking man sign".‎