Left Atrial Enlargement on EKG
EKG Characteristics of Left Atrial Abnormality
- Left atrial abnormality typically involves prolongation of total atrial activation time, as left atrial activation begins and ends later than right atrial activation 3
- The American College of Cardiology and the American Heart Association recommend considering P-wave duration ≥120 ms as a criterion for left atrial abnormality 1, 2
- A notched P wave with a peak-to-peak interval ≥40 ms (widely notched P wave) is a common EKG finding in left atrial abnormality 1, 2
- Increased P terminal force in lead V1 (product of amplitude and duration of the terminal negative component) is associated with left atrial abnormality 1, 3
- Left axis of the terminal P wave (30° to 90°) is a characteristic EKG finding in left atrial abnormality 1, 3
Clinical Significance
- Left atrial enlargement is associated with significant cardiovascular morbidity and mortality, including heart failure 4
- The American College of Cardiology recommends considering left atrial abnormality on EKG as a risk factor for stroke 5
Clinical Conditions Associated with LAE
- Valvular heart disease, particularly mitral valve disease, is a common cause of left atrial enlargement 1, 2
- Left ventricular dysfunction is associated with left atrial abnormality 1, 2
- Congenital heart disease is a potential cause of left atrial enlargement 1, 2
Recommendations for Clinical Practice
- The American Heart Association recommends using the term "left atrial abnormality" instead of "left atrial enlargement" or "atrial hypertrophy" 1, 3
- Multiple EKG criteria should be used for improved diagnostic accuracy of left atrial abnormality 1, 3
- The American College of Cardiology recommends further evaluation with echocardiography when left atrial enlargement is detected on EKG 6, 7
- In patients with suspected heart disease, an EKG showing left atrial abnormality should prompt evaluation for underlying conditions such as hypertension, valvular disease, or heart failure 4