Left Atrial Enlargement (LAE) on ECG

Introduction

Left atrial enlargement (LAE) is a condition where the left atrium of the heart becomes larger than normal. This enlargement is often caused by underlying heart conditions, such as hypertension, mitral valve disease, or heart failure. An electrocardiogram (ECG) can help detect LAE by displaying characteristic changes in the P wave.

Causes of Left Atrial Enlargement

Common causes of LAE include: - Hypertension: High blood pressure increases the workload of the heart, leading to atrial enlargement. - Mitral Valve Disorders: Conditions like mitral stenosis or regurgitation can cause increased pressure in the left atrium. - Heart Failure: When the heart weakens, blood backs up into the atria, causing dilation. - Atrial Fibrillation: Chronic arrhythmias can lead to structural changes in the atria.

ECG Features of LAE

P wave abnormalities seen in LAE:

1. Broad, notched P wave in lead II (P mitrale):
   • Appearance of a biphasic or notched P wave (>120 ms in duration).
2. Biphasic P wave in lead V1:
   • The terminal negative deflection (>1 mm deep and >40 ms in duration) is a key sign of LAE.
3. Increased P wave duration (>120 ms):
   • This suggests prolonged atrial depolarization due to enlargement.

Possible Symptoms

While LAE itself may not directly cause symptoms, the underlying conditions can lead to: - Shortness of breath (dyspnea) - Irregular heartbeats (palpitations) - Fatigue

Diagnosis and Management

• Echocardiography is the gold standard for confirming LAE and assessing its severity.
• Management focuses on treating the underlying cause:
  • Blood pressure control with medications like ACE inhibitors or beta-blockers.
  • Management of valve disorders, sometimes requiring surgery.
  • Treatment of atrial fibrillation if present.
  • Lifestyle modifications including weight control, exercise, and salt restriction.

Conclusion

LAE detected on ECG often signals an underlying cardiac disorder requiring further assessment. Early diagnosis and management can help improve heart function and long-term prognosis.

Source recommendations

1. American Heart Association Guidelines on Hypertension

1. https://www.heart.org/en/health-topics/high-blood-pressure
2. https://www.ahajournals.org/doi/10.1161/hyp.0000000000000065
3. https://www.heart.org/-/media/Files/Professional/Quality-Improvement/Pain-Management/AHA-GUIDELINEDRIVEN-MANAGEMENT-OF-HYPERTENSION--AN-EVIDENCEBASED-UPDATE.pdf
4. https://professional.heart.org/en/science-news/2017-hypertension-clinical-guidelines
5. https://pubmed.ncbi.nlm.nih.gov/29133356/

2. European Society of Cardiology Guidelines on Atrial Fibrillation

1. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Atrial-Fibrillation
2. https://academic.oup.com/eurheartj/article/42/5/373/5899003
3. https://www.escardio.org/static-file/Escardio/Guidelines/Documents/ehaa612.pdf
4. https://academic.oup.com/eurheartj/article/45/36/3314/7738779
5. https://pubmed.ncbi.nlm.nih.gov/20802247/