Restrictive Cardiomyopathy (RCM)
Details
Restrictive cardiomyopathy (RCM) is a rare cardiomyopathy phenotype defined by restrictive LV and/or RV pathophysiology in the presence of normal or reduced diastolic volumes, normal or reduced systolic volumes, and normal ventricular wall thickness. It commonly presents with biatrial enlargement and progressive diastolic dysfunction, often leading to end-stage heart failure requiring transplantation.
Key Facts
Diagnosis
- Defined by: restrictive physiology + normal/reduced diastolic volumes + normal/reduced systolic volumes + normal wall thickness. (sources/esc-cmp-2023)
- Restrictive physiology may not be present throughout the disease course; initial stages can evolve toward a hypokinetic-dilated phase. (sources/esc-cmp-2023)
- If restrictive physiology occurs in end-stage HCM or DCM, the preferred terms are "HCM with restrictive physiology" or "DCM with restrictive physiology" — not RCM. (sources/esc-cmp-2023)
- Common presentation: biatrial enlargement, preserved LVEF initially, progressive dyspnoea.
- RV and LV apical obliteration with endocardial LGE on CMR suggests endomyocardial fibrosis (EMF) or hypereosinophilia. (sources/esc-cmp-2023)
Genetics
- Causative genes include: sarcomeric variants (MYH7, TNNI3, TNNT2), DES, FLNC, BAG3, RASopathies (PTPN11, RAF1). (sources/esc-cmp-2023)
- Childhood incidence: ~0.0003% — very rare. (sources/esc-cmp-2023)
Management
- Management is largely supportive: diuretics for congestion, anticoagulation for AF/thrombus risk.
- Pulmonary vascular resistance (PVR) study is recommended to guide transplantation timing (elevated PVR contraindicates orthotopic transplantation). (sources/esc-cmp-2023)
- Cardiac transplantation is the definitive treatment; early referral is recommended due to rapid progression. (sources/esc-cmp-2023)
- Endomyocardial biopsy may be needed to diagnose eosinophilic myocarditis, giant cell myocarditis, or infiltrative disease. (sources/esc-cmp-2023)
Contradictions / Open Questions
- Restrictive physiology evolves to hypokinetic-dilated phase — diagnostic timing challenge: RCM is defined in part by preserved wall thickness and normal/reduced diastolic volumes, but the same patient may transition to a hypokinetic-dilated phase over time. This phenotypic evolution means an initial RCM label may become diagnostically inappropriate as disease progresses, and the preferred nomenclature shifts to "HCM with restrictive physiology" or "DCM with restrictive physiology" — creating classification discontinuity across the disease course that complicates longitudinal management and research cohort definitions. (sources/esc-cmp-2023)
- No randomized trial data for any specific RCM management strategy: Management of RCM is largely supportive (diuretics for congestion, anticoagulation for AF/thrombus), with cardiac transplantation as the definitive therapy. No RCT exists for any specific medical intervention in RCM. Pulmonary vascular resistance assessment guides transplant eligibility but the timing of transplant referral is guided by expert consensus, not evidence-based thresholds. (sources/esc-cmp-2023)
- RCM vs. infiltrative cardiomyopathy overlap — biopsy not always definitive: RCM differential diagnosis includes infiltrative conditions (amyloidosis, hemochromatosis, Fabry disease, sarcoidosis, eosinophilic myocarditis, giant cell myocarditis), all of which require different treatments. Endomyocardial biopsy is recommended but may have sampling error, particularly in patchy infiltrative diseases like sarcoidosis and giant cell myocarditis. A non-diagnostic biopsy in an RCM patient does not reliably exclude infiltrative disease. (sources/esc-cmp-2023)
Connections
- Related to entities/ATTR-Amyloidosis
- Related to entities/Anderson-Fabry-Disease
- Related to concepts/Phenotypic-Approach-to-Cardiomyopathy
- Related to concepts/Late-Gadolinium-Enhancement
- Related to concepts/Constrictive-vs-Restrictive — haemodynamic differentiation from constrictive pericarditis