From the Guidelines
Left atrial enlargement is not directly visible on an electrocardiogram (EKG), but rather suggested by specific changes in the P wave, such as a wider than normal P wave or a notched/biphasic P wave in lead V1, as recommended by the American Heart Association 1.
Key Points to Consider
- The American Heart Association recommends referring to abnormal P waves as "atrial abnormality" rather than "enlargement", "overload", "strain", or "hypertrophy" 1.
- Multiple electrocardiographic criteria should be used to recognize atrial abnormalities, including intraatrial conduction delay 1.
- Left atrial enlargement may be indicated by changes in the P wave, but confirmation and assessment of severity and underlying cause typically require further evaluation with an echocardiogram 1.
- Echocardiography can provide more accurate measurements of left atrial size and volume, which can be used to guide treatment and monitor progression 1.
Clinical Implications
- If left atrial enlargement is suspected based on EKG findings, further evaluation with an echocardiogram is usually recommended to confirm the finding and assess its severity and underlying cause.
- Treatment is directed at the underlying condition rather than the left atrial enlargement itself, which may include blood pressure management, heart failure treatment, or addressing valve abnormalities.
- Regular follow-up with a cardiologist is important to monitor progression and adjust treatment as needed.
From the Research
Left Atrial Enlargement on Electrocardiogram (EKG)
- Left atrial enlargement (LAE) is associated with hypertension and an increased risk of cardiovascular morbidity and mortality 2.
- The diagnostic performance of ECG criteria for identifying anatomical LAE was poor, with high negative predictive values but low sensitivity and positive predictive values 2.
- ECG signs for anatomical LAE by CT had specificity ranging from 27 to 93%, with P-wave duration >120 ms being the best performing criterion, having a sensitivity of 48% and a specificity of 78% 2.
Comparison with Other Diagnostic Modalities
- A study compared the diagnostic accuracy of ECG criteria for LAE with 2-dimensional echocardiography, finding that ECG correctly diagnosed 68 patients as positive for LAE and 12 as negative, with a sensitivity of 54.4% and a specificity of 57.1% 3.
- Another study used cardiac magnetic resonance imaging (CMR) as the gold standard and found that the sensitivity of individual ECG criteria for LAE was low, with the best performing criterion being P > 120 ms, having a sensitivity of 49.6% 4.
- Echocardiographic left atrial enlargement was found to be an early sign of hypertensive heart disease, even in patients with no other discernible cause of left atrial enlargement 5.
Association with Left Ventricular Hypertrophy and Diastolic Dysfunction
- Left atrial enlargement is a powerful risk factor for cardiovascular diseases and is strongly related to left ventricular hypertrophy (LVH) and diastolic dysfunction 6.
- A study found that LAE is a frequent finding in patients with preserved systolic function, and this abnormality is strongly related to LVH and diastolic dysfunction, with early detection of LAE potentially identifying patients at higher cardiovascular risk 6.