Restrictive Cardiomyopathy

Restrictive cardiomyopathy (RCM) requires persistent restrictive LV physiology with diastolic dysfunction, nondilated ventricles, and atrial enlargement. Ventricular wall thickness and systolic function do not define the phenotype: infiltration, intracellular storage, or cardiomyocyte hypertrophy can all increase wall thickness, and restrictive physiology may emerge early or late in a disease course. ESC+1ESCESC 365 - Restrictive cardiomyopathy: definition and diagnosisPubMedRestrictive cardiomyopathy: definition and diagnosis - PMC

Start with 12-lead ECG and transthoracic echocardiography with Doppler assessment of filling physiology, chamber size, wall thickness, systolic function, and valve disease. Doppler echocardiography or cardiac catheterization can demonstrate restrictive pathophysiology; use the full clinical-imaging pattern rather than ventricular wall thickness alone. ESCESCESC 365 - Restrictive cardiomyopathy: definition and diagnosis

Before diagnosing RCM, actively evaluate competing phenotypes. Hypertensive heart disease and hypertrophic cardiomyopathy must be excluded, and constrictive pericarditis remains a critical alternative because it can mimic restrictive filling but has a fundamentally different procedural treatment pathway. jacc+1jaccSpectrum of Restrictive and Infiltrative Cardiomyopathies: Part 1 of a 2-Part SeriesScienceDirectCardiac MRI in restrictive cardiomyopathy - ScienceDirect

Organize the differential into four mechanistic branches: interstitial fibrosis or intrinsic myocardial dysfunction, extracellular infiltration, intracellular storage, and endomyocardial fibrosis. The common secondary causes include amyloidosis, sarcoidosis, primary or secondary hemochromatosis, Fabry disease and other storage disorders, metastatic cancer, and radiation-induced disease; idiopathic RCM and endomyocardial fibrosis are primary forms. jacc+1jaccSpectrum of Restrictive and Infiltrative Cardiomyopathies: Part 1 of a 2-Part SeriesESCESC 365 - Restrictive cardiomyopathy: definition and diagnosis

Use cardiovascular magnetic resonance (CMR), including T1, T2, and extracellular-volume mapping, when echocardiography establishes a restrictive phenotype but does not identify the substrate. CMR can reduce the diagnostic need for biopsy and provides tissue characterization relevant to amyloidosis, iron overload, sarcoidosis, and endomyocardial disorders. jacc+1jaccSpectrum of Restrictive and Infiltrative Cardiomyopathies: Part 1 of a 2-Part SeriesScienceDirectCardiac MRI in restrictive cardiomyopathy - ScienceDirect

History should drive targeted evaluation: previous chest radiation or metastatic malignancy raises radiation-related or malignant myocardial disease; systemic sarcoidosis raises cardiac sarcoidosis; iron-overload states raise hemochromatosis; neuropathy or other familial systemic manifestations raise transthyretin amyloidosis or storage disease. Cardiac amyloidosis is the most common RCM cause in developed countries, particularly among older patients with heart failure and preserved ejection fraction. jacc+1jaccSpectrum of Restrictive and Infiltrative Cardiomyopathies: Part 1 of a 2-Part SeriesPubMedRestrictive Cardiomyopathy - StatPearls - NCBI Bookshelf

Perform genetic evaluation when familial RCM or an inherited phenocopy is suspected. Familial RCM is usually autosomal dominant and has meaningful phenotype-genotype overlap with HCM; associated genetic conditions include desminopathies, hereditary hemochromatosis, and Danon disease. ACCACCDefinition and Diagnosis of Restrictive Cardiomyopathy: Key Points - American College of Cardiology

Use diuretics as the mainstay of heart-failure treatment in RCM, while simultaneously treating the underlying cause when identified. The restrictive ventricle has limited filling reserve, so reassess symptoms, blood pressure, renal function, and congestion after diuretic adjustment rather than assuming that standard heart-failure escalation will be tolerated. AHA JournalsAHA JournalsRestrictive Cardiomyopathy | Circulation Research

Obtain ECG at presentation and use ambulatory rhythm monitoring when palpitations, presyncope, or lightheadedness suggest intermittent arrhythmia. Although the periodic monitoring schedule is specified for HCM, its principles are useful in an RCM/HCM overlap phenotype: initial and follow-up ECG, 24- to 48-hour ambulatory monitoring, and monitoring longer than 24 hours or event recording when symptoms require correlation. jaccjacc2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for ... - JACC

Treat arrhythmias as part of the underlying disease pathway. Sarcoidosis requires management of inflammation with corticosteroid-based immunosuppression as well as guideline-directed heart-failure and arrhythmia therapy; infiltrative cardiomyopathies are also associated with conduction-system abnormalities and sudden cardiac death. ACC+1ACCDefinition and Diagnosis of Restrictive Cardiomyopathy: Key Points - American College of CardiologyScienceDirectSudden Cardiac Death in Infiltrative Cardiomyopathies: Sarcoidosis, Scleroderma, Amyloidosis, Hemachromatosis - ScienceDirect

For AL amyloidosis, disease-modifying treatment includes autologous stem-cell transplantation after bortezomib conditioning in eligible patients. For patients who are not transplant eligible, daratumumab, bortezomib, cyclophosphamide, and dexamethasone is a cited alternative regimen; coordinate treatment with an amyloidosis and hematology program because cardiac involvement materially affects treatment tolerance. ACCACCDefinition and Diagnosis of Restrictive Cardiomyopathy: Key Points - American College of Cardiology

For transthyretin amyloidosis, tafamidis reduces further TTR formation and prolongs survival. Patisiran and inotersen are approved for stage 1 or 2 familial TTR amyloidosis with polyneuropathy rather than specifically for cardiomyopathy in the cited guidance; patients receiving these agents require vitamin A supplementation, and inotersen- or patisiran-associated adverse effects cited include glomerulonephritis and thrombocytopenia. ACCACCDefinition and Diagnosis of Restrictive Cardiomyopathy: Key Points - American College of Cardiology

For iron-overload cardiomyopathy, pursue treatment directed at iron removal or binding because reducing ongoing iron deposition may slow myocardial injury. For cardiac sarcoidosis, pair corticosteroid-based inflammatory suppression with heart-failure and arrhythmia treatment rather than treating the restrictive physiology alone. ScienceDirect+1ScienceDirectRestrictive Cardiomyopathy - an overviewACCDefinition and Diagnosis of Restrictive Cardiomyopathy: Key Points - American College of Cardiology

For inherited and storage disorders, establish the specific genetic or metabolic diagnosis before considering targeted therapy. The RCM phenotype overlaps genetically with HCM and can arise from desminopathy, Danon disease, hereditary hemochromatosis, and other storage disorders; an etiologic label of idiopathic RCM should follow rather than precede this evaluation. jacc+1jaccSpectrum of Restrictive and Infiltrative Cardiomyopathies: Part 1 of a 2-Part SeriesACCDefinition and Diagnosis of Restrictive Cardiomyopathy: Key Points - American College of Cardiology

Refer selected patients for transplant evaluation when advanced heart failure develops despite medical and cause-directed treatment. Mechanical circulatory support is often challenging in RCM because the LV is small; transplant may therefore become the principal advanced therapy option. ACCACCDefinition and Diagnosis of Restrictive Cardiomyopathy: Key Points - American College of Cardiology

In HCM with advanced heart failure, 20% to 50% have preserved ejection fraction with restrictive physiology, so transplant referral does not require reduced ejection fraction. Patients with HCM and advanced heart failure are also less likely to receive mechanical circulatory support because of small LV size and disease-specific anatomy. jaccjacc2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for ... - JACC

ATTR and AL amyloidosis do not automatically preclude transplant evaluation. Reported post-transplant outcomes are similar across ATTR, AL, and nonamyloid cardiomyopathy cohorts, although candidacy requires assessment of systemic disease burden and the ability to address the underlying process. AHA JournalsAHA JournalsHeart Failure Subtypes and Cardiomyopathies in Women