What is the recommended echo assessment for constrictive pericarditis?

Echocardiographic Assessment of Constrictive Pericarditis

Transthoracic echocardiography is the recommended first-line imaging modality for the assessment of constrictive pericarditis, with specific focus on respiratory variation in ventricular filling, septal motion, and tissue Doppler parameters. 1

Key Echocardiographic Findings

Essential Parameters

• Septal bounce/shift: Respiration-related ventricular septal shift is pathognomonic and one of the most specific findings 2, 3
• Doppler findings:
  • Exaggerated respiratory variation (>25%) in mitral inflow E velocity 1, 2
  • E/A ratio >2 with short deceleration time 1
  • Preserved or increased medial mitral annular e' velocity (≥9 cm/s) 2, 3
  • Medial-to-lateral e' ratio ≥0.91 ("annulus reversus") 2
  • Hepatic vein expiratory diastolic reversal ratio ≥0.79 3

Mayo Clinic Diagnostic Criteria

The most accurate echocardiographic approach combines:

• Ventricular septal shift plus either:
  • Medial e' ≥9 cm/s (sensitivity 87%, specificity 91%) or
  • Hepatic vein expiratory diastolic reversal ratio ≥0.79 3

When all three parameters are present, specificity increases to 97% (though sensitivity decreases to 64%) 3

Differential Diagnosis: Constrictive Pericarditis vs. Restrictive Cardiomyopathy

Feature	Constrictive Pericarditis	Restrictive Cardiomyopathy
Septal motion	Respiratory septal bounce present	Absent
Medial e' velocity	Preserved/increased (≥9 cm/s)	Reduced (<8 cm/s)
Respiratory variation in mitral E velocity	>25%	Minimal (<10%)
Medial-to-lateral e' ratio	≥0.91 (annulus reversus)	<0.91
Propagation velocity (Vp)	>45 cm/s	<45 cm/s

1, 2, 4

Limitations of Echocardiography

• Pericardial thickness: While echocardiography can detect thickened pericardium, it has limited accuracy in measuring pericardial thickness compared to CT/MRI 1, 2
• No single diagnostic sign: A combination of findings is required for accurate diagnosis 2
• Special considerations in atrial fibrillation: In patients with atrial fibrillation, all criteria except mitral inflow velocity variation remain valid 2, 3

Recommended Diagnostic Algorithm

1. Initial assessment: Transthoracic echocardiography with respiratory monitoring 1

2. Focus on key parameters:

   • Septal bounce/shift
   • Respiratory variation in mitral inflow velocities
   • Tissue Doppler assessment of mitral annular velocities
   • Hepatic vein flow patterns

3. If findings are equivocal:

   • Proceed to CT or CMR for assessment of pericardial thickness and calcifications 1
   • Consider cardiac catheterization if non-invasive methods are inconclusive 1

Pitfalls to Avoid

• Mistaking pericardial fat pads for pericardial effusion (fat pads typically show internal echoing) 2
• Confusing the descending aorta for posterior effusion 2
• Relying on a single echocardiographic parameter rather than the constellation of findings 2
• Failing to correlate echocardiographic findings with clinical presentation and other imaging modalities 1

Post-Pericardiectomy Assessment

Echocardiography is valuable for monitoring response to pericardiectomy:

• Normalization of Doppler findings after surgery correlates with good functional outcomes 5
• Persistent restrictive Doppler features post-surgery may indicate incomplete pericardiectomy or myocardial involvement 5

By systematically evaluating these echocardiographic parameters, clinicians can accurately diagnose constrictive pericarditis and differentiate it from other causes of diastolic heart failure, particularly restrictive cardiomyopathy.