Left atrial enlargement electrocardiogram


 * Associate Editor-In-Chief:

Overview
Left atrial enlargement may be observed among patients with pressure or volume overload of the left atrium.

Differential Diagnosis of Left Atrial Enlargement

 * Atrial aneurysm
 * Infective endocarditis
 * Left heart failure
 * Mitral regurgitation
 * Mitral stenosis
 * Mitral valve prolapse
 * Myxedema
 * Patent Ductus Arteriosus
 * Ventricular septal defect

EKG in Left Atrial Enlargement
1. LA enlargement: Left atrial enlargement produces a broad, bifid P wave in lead II (P mitrale) and enlarges the terminal negative portion of the P wave in VI.

In lead I and/or II following may be seen:
 * Bifid P wave with > 40 ms between the two peaks
 * Total P wave duration > 110 ms

In lead V1, the following may be seen:
 * Biphasic P wave with terminal negative portion > 40 ms duration (>0.04 sec or 1 small square)
 * Biphasic P wave with terminal negative portion > 1mm deep