Understanding Acute Pericarditis and ECG Findings

Introduction

Acute pericarditis is an inflammation of the pericardium, the thin sac surrounding the heart. It can be caused by viral infections, autoimmune diseases, trauma, or other underlying conditions. One of the key diagnostic tools for acute pericarditis is the electrocardiogram (ECG), which shows characteristic changes during the course of the illness.

Causes of Acute Pericarditis

• Infections: Viral (Coxsackievirus, Echovirus), Bacterial (Tuberculosis, Pneumococcal), Fungal
• Autoimmune Diseases: Lupus, Rheumatoid arthritis, Scleroderma
• Other Causes: Post-myocardial infarction (Dressler syndrome), Uremia, Trauma, Cancer metastasis

Clinical Symptoms

• Chest Pain: Sharp, pleuritic pain that worsens with inspiration or lying down and improves when sitting up and leaning forward.
• Pericardial Friction Rub: A scratchy sound heard during auscultation due to inflamed pericardial layers rubbing against each other.
• Fever: Often present in infectious cases.
• Dyspnea: Shortness of breath due to discomfort and inflammation.

ECG Changes in Acute Pericarditis

The ECG findings in acute pericarditis generally progress through four stages:

Stage 1

• Diffuse ST-segment elevation (concave upwards, affecting multiple leads except aVR and V1)
• PR-segment depression (most notable in lead II, opposite in aVR)

Stage 2

• ST segments begin to normalize
• PR-segment changes may still be visible

Stage 3

• T-wave inversions occur (not always present in all patients)

Stage 4

• ECG returns to a normal baseline

Differential Diagnosis

ECG findings in pericarditis can sometimes be confused with:

• Myocardial Infarction: ST-elevation in myocardial infarction (STEMI) affects specific territories rather than diffusely and is often associated with reciprocal ST depressions.
• Early Repolarization: Benign ECG variant sometimes mimicking pericarditis.

Diagnostic Workup

To confirm acute pericarditis, the following tests are useful:

• Echocardiography: Evaluates pericardial effusion.
• Blood Tests: Inflammatory markers (CRP, ESR, leukocytosis), cardiac enzymes (to rule out myocarditis or infarction).
• Chest X-ray: Assess for pericardial effusion in advanced cases.
• MRI/CT Scan: Helps in complicated or recurrent cases.

Treatment

• NSAIDs (Ibuprofen, Aspirin): First-line treatment to reduce inflammation.
• Colchicine: Reduces recurrence risk.
• Glucocorticoids: Reserved for refractory or autoimmune cases.
• Pericardiocentesis: If there is a large symptomatic pericardial effusion.
• Antibiotics or Antiviral Therapy: If infection is identified.

Prognosis

Most cases of acute pericarditis resolve within a few weeks with appropriate treatment, but some may develop recurrent or chronic pericarditis.

Conclusion

ECG is a crucial tool in diagnosing acute pericarditis, displaying characteristic ST-segment elevations and PR-segment depressions. Prompt evaluation and appropriate treatment are essential to prevent complications such as cardiac tamponade or chronic pericarditis.

Source recommendations

1. American College of Cardiology/American Heart Association (ACC/AHA) Guidelines for the Diagnosis and Treatment of Pericardial Diseases

1. https://www.ahajournals.org/doi/10.1161/CIR.0000000000001106
2. https://www.acc.org/Latest-in-Cardiology/ten-points-to-remember/2020/01/07/10/59/Management-of-Acute-and-Recurrent-Pericarditis
3. https://www.jacc.org/doi/10.1016/j.jacc.2024.10.080
4. https://www.acc.org/latest-in-cardiology/ten-points-to-remember/2015/10/30/12/01/2015-esc-guidelines-for-the-diagnosis-and-management-of-pericardial-diseases
5. https://pubmed.ncbi.nlm.nih.gov/33332149/

2. European Society of Cardiology (ESC) Guidelines for the Management of Pericardial Diseases

1. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Pericardial-Diseases-Guidelines-on-the-Diagnosis-and-Management-of
2. https://academic.oup.com/eurheartj/article/36/42/2921/2293375
3. https://pubmed.ncbi.nlm.nih.gov/26320112/
4. https://www.escardio.org/Working-groups/Working-Group-on-Myocardial-and-Pericardial-Diseases/Publications/Paper-of-the-Month/2015-esc-guidelines-on-the-diagnosis-and-management-of-pericardial-diseases
5. https://www.acc.org/latest-in-cardiology/ten-points-to-remember/2015/10/30/12/01/2015-esc-guidelines-for-the-diagnosis-and-management-of-pericardial-diseases