What type of pericarditis may present with a normal electrocardiogram (ECG)?

Uremic Pericarditis Typically Presents with a Normal ECG

Uremic pericarditis is the type of pericarditis that most commonly presents with a normal electrocardiogram (ECG). 1, 2, 3

Distinguishing ECG Features in Different Types of Pericarditis

Uremic Pericarditis

• Normal ECG pattern is characteristic of uremic pericarditis 1
• Unlike other forms of pericarditis, uremic pericarditis lacks the typical ECG changes because it does not involve myocardial inflammation 1
• The European Society of Cardiology guidelines specifically note that "if the ECG is typical of acute pericarditis, intercurrent infection must be suspected" in uremic patients 1
• Recent case studies confirm that uremic pericarditis patients often present with normal electrocardiography despite having other clinical manifestations of pericarditis 2

Rheumatic Pericarditis

• Usually shows the classic ECG changes of acute pericarditis
• Typically presents with diffuse ST-segment elevations and PR-segment depressions
• Follows the four classic stages of ECG evolution in pericarditis 1

Post-MI Pericarditis (Dressler Syndrome)

• Characterized by typical ECG changes of acute pericarditis
• However, these changes may be difficult to distinguish from the underlying MI changes
• Usually shows ST-segment elevations that are concave upward, unlike the convex pattern seen in acute MI 1

Diagnostic Criteria for Acute Pericarditis

According to the European Society of Cardiology guidelines, acute pericarditis is diagnosed when at least 2 of the following criteria are present 1, 4:

1. Typical chest pain (sharp, pleuritic, improved by sitting forward)
2. Pericardial friction rub
3. Suggestive ECG changes (widespread ST elevation or PR depression)
4. New or worsening pericardial effusion

Why Uremic Pericarditis Presents with Normal ECG

• Uremic pericarditis primarily affects the pericardium without significant myocardial involvement 1, 2
• The pericardium itself is electrically silent; ECG changes in pericarditis generally reflect concurrent myocardial inflammation 5
• In uremic pericarditis, the inflammation is predominantly limited to the pericardial layers without extending to the myocardium 3
• Recent research shows that ECG changes are present in only about 25% of patients with pure pericarditis, but in about 60% of patients with myopericarditis 5

Clinical Implications and Management

• The absence of typical ECG changes in a patient with suspected pericarditis should raise suspicion for uremic pericarditis, especially in patients with known or undiagnosed kidney disease 2
• Uremic pericarditis requires different management than other forms of pericarditis:
  • Intensification of dialysis is the primary treatment (Class IIa recommendation) 1
  • NSAIDs and corticosteroids should be considered only when intensive dialysis is ineffective (Class IIb) 1
  • Colchicine is contraindicated in patients with severe renal impairment 1

Diagnostic Pitfalls to Avoid

• Don't rule out pericarditis based on a normal ECG, especially in patients with renal failure 2, 6
• Be aware that uremic pericarditis patients may not present with tachycardia even during cardiac tamponade, making diagnosis more challenging 2
• Serial ECGs may be necessary as changes can evolve over time or appear during episodes of chest pain 6
• Echocardiography is essential for diagnosis, as it can detect pericardial effusion even when ECG is normal 1, 4

Key Takeaway

When evaluating a patient with suspected pericarditis and a normal ECG, uremic pericarditis should be high on the differential diagnosis, particularly if the patient has risk factors for or known kidney disease. The absence of typical ECG changes does not rule out pericarditis but may help narrow the etiology to uremic causes.