AKA: Left atrial hypertrophy, left atrial abnormality.
Attention! Before reading this page, check out our introduction to the P wave for an explanation of the basics of atrial enlargement.
- Left atrial enlargement (LAE) is due to pressure or volume overload of the left atrium.
- It is often a precursor to atrial fibrillation.
LAE produces a broad, bifid P wave in lead II (P mitrale) and enlarges the terminal negative portion of the P wave in V1.
Diagnostic criteria are as follows:
In lead II
- Bifid P wave with > 40 ms between the two peaks
- Total P wave duration > 110 ms
- Biphasic P wave with terminal negative portion > 40 ms duration
- Biphasic P wave with terminal negative portion > 1mm deep
- Classically seen with mitral stenosis
In association with left ventricular hypertrophy:
- Systemic hypertension
- Aortic stenosis
- Mitral incompetence
- Hypertrophic cardiomyopathy
- ECG BASICS – Waves, Intervals, Segments and Clinical Interpretation
- ECG CLINICAL CASES – Your favourite ECG’s placed in clinical context with a challenging Q&A approach
- ECG and Cardiology Eponymous Syndromes – Cheats guide to eponymous emancipation
- ECG Reference Sites on the WEB – the best of the rest
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