Left atrial enlargement (LAE)
Also calledLAE · left atrial abnormality · LAA
Definition
Left atrial enlargement (also called left atrial abnormality) is an ECG pattern of delayed, prolonged left atrial activation. Because left atrial activation begins and ends later than right atrial activation, the delay lengthens the P wave and tends to make it notched or double-peaked. Criteria (each is used on its own): a P-wave duration of 120 ms or more in lead II, often with a notch whose two peaks are 40 ms or more apart; or an enlarged terminal negative component of the P wave in V1, measured as the P-terminal force (depth times duration), with values of 0.04 mm·s or more (a negative area of at least one small square, 1 mm²) regarded as abnormal.
Sources
- Hancock EW, Deal BJ, Mirvis DM, et al. AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part V: electrocardiogram changes associated with cardiac chamber hypertrophy. Circulation. 2009;119(10):e251-e261. doi.org/10.1161/CIRCULATIONAHA.108.191097
- Eranti A, Aro AL, Kerola T, et al. Prevalence and prognostic significance of abnormal P terminal force in lead V1 of the ECG in the general population. Circ Arrhythm Electrophysiol. 2014;7(6):1116-1121. doi.org/10.1161/CIRCEP.114.001557
- Samesima N, God EG, Kruse JCL, et al. Brazilian Society of Cardiology guidelines on the analysis and issuance of electrocardiographic reports - 2022. Arq Bras Cardiol. 2022;119(4):638-680. doi.org/10.36660/abc.20220623
Last reviewed 2 October 2026. Every definition in the EKG Dictionary cites the guideline, consensus statement or original paper it comes from.