What are the guidelines for using echocardiography (echo) in diagnosing and managing pericardial diseases?

Echocardiography Guidelines for Pericardial Diseases

Transthoracic echocardiography is the first-line imaging test in patients with suspected pericardial disease, as it accurately detects pericardial effusion, cardiac tamponade, and ventricular dysfunction due to myocardial involvement. 1

Role of Echocardiography in Pericardial Diseases

Primary Diagnostic Tool

• Echocardiography provides the most cost-effective way of diagnosing pericardial effusion and assessing its hemodynamic significance 1
• Two-dimensional echocardiography with Doppler is essential for evaluating pericardial diseases and should be performed in all patients with suspected pericardial effusion 1
• Although patients with purely fibrinous acute pericarditis may have a normal echocardiogram, the presence of a pericardial effusion is consistent with acute pericarditis and is one of the criteria for its diagnosis 1

Assessment of Pericardial Effusion

• Pericardial effusion size is qualitatively assessed by the end-diastolic distance of the echo-free space between epicardium and parietal pericardium: small (<10 mm), moderate (10-20 mm), large (>20 mm) 1
• Images should be documented digitally and the effusion size described in detail in the echocardiographic report, including both extent and location of each measurement 1
• Hemodynamic tolerance is more related to the rapidity of appearance of the effusion than to its total volume 1

Cardiac Tamponade Diagnosis

• Echocardiographic signs of tamponade include: swinging of the heart, early diastolic collapse of the right ventricle, late diastolic collapse of the right atrium, abnormal ventricular septal motion, exaggerated respiratory variability in mitral inflow velocity, and inferior vena cava plethora 1
• Echo-guided pericardiocentesis is the gold standard method for drainage of pericardial effusion in the presence of cardiac tamponade 2

Specific Echocardiographic Findings in Pericardial Diseases

Acute Pericarditis

• Key findings include thickened pericardial layers, variable amount of pericardial effusion, and wall motion abnormalities in myopericarditis 1
• Echocardiography may help differentiate acute pericarditis from myocardial ischemia by excluding wall motion abnormalities consistent with coronary flow distribution 1
• Note that 5% of patients with acute pericarditis and myocardial involvement may demonstrate wall motion abnormalities 1

Constrictive Pericarditis

• Echocardiographic findings include thickened pericardial layers, ascites, dilated atria, and inspiratory ventricular septal motion toward left ventricle (septal bounce) best documented with M-mode 1
• Additional findings include marked dilation and absent or diminished collapse of the IVC and hepatic veins, and premature opening of the pulmonary valve 1
• Tissue Doppler analysis (TDI) improves the differentiation of constriction from restrictive myocardial disease by assessment of early diastolic annulus velocity and annulus reversus 3

Recurrent Pericarditis

• Echocardiography may reveal adhesions between pericardial layers 1
• Follow-up echocardiography is important to monitor disease progression and response to treatment 2

Advanced Echocardiographic Techniques

Newer Modalities

• Cardiac tissue Doppler analysis (TDI), strain and strain rate imaging by speckle tracking (STE), and three-dimensional (3D) echocardiography represent significant advances in echocardiographic assessment of pericardial diseases 3
• 3D echocardiography provides more precise assessment of pericardial effusion or masses by detecting anatomic structures with higher accuracy 3
• Speckle tracking echocardiography serves as a complementary tool to differentiate constrictive pericarditis from restrictive cardiomyopathy 3

Special Considerations

• Loculated pericardial effusions or pericardial effusions containing clots (e.g., after cardiac surgery) may be difficult to diagnose using a transthoracic approach and may require transesophageal echocardiography 1
• Echo-guided pericardiocentesis significantly improves safety and efficacy of the procedure 4

Complementary Imaging Modalities

When to Consider Additional Imaging

• CT or CMR should be considered in suspected cases of loculated pericardial effusion, pericardial thickening and masses, as well as associated chest abnormalities 1
• CT is the most accurate technique to image calcified tissue and is essential in the preoperative work-up of some patients with constrictive pericarditis 1
• CMR provides comprehensive assessment allowing visualization and tissue characterization of the pericardium and appraisal of the consequences of pericardial abnormalities on cardiac function 1

Common Pitfalls and Caveats

• Pericardial fat can mimic pericardial effusion, requiring careful evaluation 5
• The haemodynamic tolerance of pericardial effusion relates more to the rapidity of appearance than to its total volume 1
• Purely fibrinous acute pericarditis may present with a normal echocardiogram, so absence of effusion does not exclude pericarditis 1
• Differentiation between constrictive pericarditis and restrictive cardiomyopathy can be challenging and may require multiple echocardiographic parameters and sometimes additional imaging modalities 3