Left Atrial Enlargement

Left Atrial Enlargement

Left atrial enlargement (LAE) is due to pressure or volume overload of the left atrium. LAE is often a precursor to atrial fibrillation.

Also known as: Left Atrial Enlargement (LAE), Left atrial hypertrophy (LAH), left atrial abnormality.


P wave changes with Left Atrial Enlargement

ECG Criteria for Left Atrial Enlargement

LAE produces a broad, bifid P wave in lead II (P mitrale) and enlarges the terminal negative portion of the P wave in V1.

In lead II

  • Bifid P wave with > 40 ms between the two peaks
  • Total P wave duration > 110 ms

In V1

  • Biphasic P wave with terminal negative portion > 40 ms duration
  • Biphasic P wave with terminal negative portion > 1mm deep

Causes of left atrial hypertrophy

In isolation:

  • Classically seen with mitral stenosis

In association with left ventricular hypertrophy:

  • Systemic hypertension
  • Aortic stenosis
  • Mitral incompetence
  • Hypertrophic cardiomyopathy

ECG Examples

Example 1
  • Broad (>110ms), bifid P wave in lead II (P mitrale) with > 40ms between the peaks

Example 2

P wave terminal portion
P wave terminal portion > 40 ms duration in V1

Example 3

P waves with terminal portion more than 1mm deep in V1
P waves with terminal portion > 1mm deep in V1

Related Topics


References

Advanced Reading

Online

Textbooks


LITFL Further Reading

ECG LIBRARY 700

ECG LIBRARY

Electrocardiogram

Emergency Physician in Prehospital and Retrieval Medicine in Sydney, Australia. He has a passion for ECG interpretation and medical education | ECG Library |

MBBS (UWA) CCPU (RCE, Biliary, DVT, E-FAST, AAA) Emergency Medicine Advanced Trainee in Melbourne, Australia. Special interests in diagnostic and procedural ultrasound, medical education, and ECG interpretation. Editor-in-chief of the LITFL ECG Library. Twitter: @rob_buttner

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.