Tissue Doppler Values in Restrictive Cardiomyopathy
In advanced restrictive cardiomyopathy, tissue Doppler demonstrates severely reduced mitral annular e′ velocities of 3-4 cm/s at both septal and lateral sites, with a characteristic pattern showing higher lateral e′ compared to septal e′ (unlike constrictive pericarditis), combined with an E/e′ ratio >14. 1
Key Tissue Doppler Characteristics
Early Diastolic Velocity (e′)
- Septal e′: 3-4 cm/s in advanced disease 1
- Lateral e′: 3-4 cm/s in advanced disease 1
- Critical diagnostic pattern: Lateral e′ > septal e′ (termed "annulus reversus") distinguishes RCM from constrictive pericarditis where septal e′ is typically higher 1
- Cutoff value <8 cm/s at both septal and lateral annulus has 95% sensitivity and 96% specificity for restrictive cardiomyopathy versus constrictive pericarditis 2
Systolic Velocity (S′)
- Markedly reduced S′ velocities: Septal S′ approximately 4.1 ± 1.5 cm/s and lateral S′ approximately 4.3 ± 1.9 cm/s 3
- Combined cutoff <8 cm/s for both S′ and e′ at lateral and septal annulus demonstrates 93% sensitivity and 88% specificity for RCM diagnosis 3
E/e′ Ratio
- E/e′ ratio >14 indicates markedly elevated left atrial pressure 1
- This ratio is significantly elevated in RCM (approximately 25.1 ± 8.7) compared to constrictive pericarditis (11.2 ± 8.8) 4
Disease Stage Variations
Early Stage RCM
- Diastolic function may show Grade 1 dysfunction (impaired relaxation with normal LV filling pressures) 1
- Can progress to Grade 2 dysfunction (pseudonormalization pattern) 1
Advanced Stage RCM (Grade 3 Diastolic Dysfunction)
- Restrictive filling pattern with mitral E/A ratio >2.5 1
- Deceleration time (DT) <150 msec (often <140 msec for high specificity) 1
- Isovolumic relaxation time (IVRT) <50 msec (high specificity) 1
- Severely reduced e′ velocities as described above 1
- LA volume index >50 mL/m² (markedly increased) 1
Critical Diagnostic Pitfalls
The presence of normal or near-normal annular e′ velocity (≥8 cm/s) in a patient with suspected heart failure should raise strong suspicion for constrictive pericarditis rather than restrictive cardiomyopathy. 1 This is the single most important distinguishing feature.
Subtype Differences
In cardiac amyloidosis specifically, e′ velocities are even lower (4.6 cm/s) compared to primary restrictive cardiomyopathy (6.3 cm/s), though both remain well below the 8 cm/s threshold 2. There is often no overlap in e′ values between constrictive pericarditis and cardiac amyloidosis 2.
Prognostic Significance
Grade 3 diastolic dysfunction with these severely reduced tissue Doppler values is associated with poor outcomes in restrictive cardiomyopathy patients. 1 The combination of restrictive physiology on conventional Doppler with profoundly reduced tissue velocities indicates advanced myocardial disease with markedly elevated filling pressures 1.
Measurement Technique Considerations
- Measurements should be obtained at both septal and lateral mitral annulus using pulsed-wave tissue Doppler 1, 3, 4
- Sweep speed of 100 mm/sec is recommended for accurate measurements 1
- The e′ velocity must be distinguished from biphasic velocity during isovolumic relaxation period 1
- Gain and filter settings should be optimized to avoid high gain that can distort measurements 1