What are the echocardiographic differences between pericarditis and myocarditis?

From the Guidelines

Echocardiography is the first-line imaging test for differentiating between pericarditis and myocarditis, as it can accurately detect pericardial effusion, cardiac tamponade, and ventricular dysfunction due to myocardial involvement 1.

Key Echocardiographic Findings

• In pericarditis, echocardiography typically shows pericardial effusion, pericardial thickening, and sometimes fibrinous strands within the effusion, with normal ventricular function in isolated pericarditis 1.
• In myocarditis, echocardiography often presents with regional or global wall motion abnormalities, ventricular dilation, and reduced ejection fraction, with left ventricular dysfunction being a hallmark finding 1.
• The size of pericardial effusion on two-dimensional echocardiography is qualitatively assessed by the end-diastolic distance of the echo-free space between the epicardium and parietal pericardium, with small, moderate, and large effusions defined as <10 mm, 10-20 mm, and >20 mm, respectively 1.

Diagnostic Considerations

• A normal echocardiogram does not exclude the diagnosis of pericarditis, as pericardial effusion is detectable in only 60% of cases 1.
• Pericardial thickening (>3 mm) may be present in pericarditis, although echocardiography is not accurate, and transesophageal echocardiography (TOE) is superior to transthoracic echocardiography (TTE) for detecting pericardial thickening 1.
• Speckle tracking imaging and real-time, low-mechanical-index myocardial contrast echocardiography are promising non-invasive methods for identifying areas of intramyocardial inflammation in patients with acute myocarditis 1.

Clinical Implications

• Serial echocardiograms may be needed to monitor disease progression and treatment response in both pericarditis and myocarditis.
• Echocardiography can help differentiate between pericarditis and myocarditis, allowing for targeted treatment and management of these distinct inflammatory heart conditions.

From the Research

Echocardiography in Pericarditis and Myocarditis

• Echocardiography is a crucial tool in diagnosing and managing pericardial diseases, including pericarditis and myocarditis 2.
• It can help assess pericardial effusion, tamponade, and constrictive pericarditis, as well as myocardial dysfunction associated with myocarditis.
• Newer echocardiographic techniques, such as cardiac tissue Doppler analysis, strain and strain rate imaging, and three-dimensional echocardiography, can provide more accurate assessments of pericardial diseases 2.

Differentiating Pericarditis and Myocarditis

• Pericarditis and myocarditis can present with similar symptoms, such as chest pain and elevated cardiac enzymes, making diagnosis challenging 3, 4.
• Echocardiography can help differentiate between the two conditions by identifying pericardial effusion, tamponade, or myocardial wall motion abnormalities.
• Electrocardiographic changes, such as ST-segment elevation, can also be helpful in diagnosing pericarditis and myocarditis, but may not always be specific 3, 4.

Diagnostic Criteria

• The diagnosis of myocarditis can be suggested by presenting symptoms, elevated biomarkers such as troponins, electrocardiographic changes, and echocardiographic wall motion abnormalities or wall thickening 5.
• Cardiac magnetic resonance imaging or endomyocardial biopsy may be required for definitive diagnosis of myocarditis 5.
• Pericarditis can be diagnosed based on clinical presentation, electrocardiographic changes, and echocardiographic findings, such as pericardial effusion or tamponade 3, 4.