5th July 2026

Restrictive cardiomyopathy

• Least common form of cardiomyopathy.
• Age: It can affect individuals of all ages, but is more commonly diagnosed in older adults.
• Gender: There is no significant gender predilection.

Restrictive cardiomyopathy (RCM) is a heterogeneous group of diseases typified by the presence of myocardial stiffness with diastolic dysfunction and raised filling pressures. This is often accompanied by atrial dilatation and non-dilated ventricles, irrespective of ventricular wall thickness and systolic function. These pathophysiological processes result in pulmonary hypertension, which can potentiate right heart failure. LV ejection fraction (LVEF) is typically preserved in RCM, but can deteriorate over time in the late stages of the disease. Compliance is reduced in RCM, which affects LV filling and stroke volume. Patients with autonomic dysfunction may experience hypotension during exercise as the ability to raise heart rate to improve cardiac output is impaired. Chronic diastolic dysfunction contributes to atrial remodelling and dilatation, resulting in atrial fibrillation (AF). 

Aetiology

RCM can be idiopathic or caused by mutations in genes related to sarcomeric proteins, but also infiltrative diseases, storage diseases, connective tissue disorders, hypereosinophilic syndrome and endomyocardial fibrosis. 

• Genetic
  • Primary RCM
• Drugs
  • Hydroxychloroquine
  • Ergotamine
  • Methysergide
• Systemic disease
  • Amyloidosis
  • Sarcoidosis
  • Friedrich’s ataxia
  • Haemochromatosis
  • Fabry’s disease
• Fibrosis
  • Radiation
  • Chemotherapy (e.g. anthracyclines)
  • Malignancy
  • Systemic sclerosis
  • Diabetes mellitus
  • Inflammatory/granulomatous
• Endomyocardial disease
  • Endomyocardial fibrosis
  • Carcinoid
  • Hypereosinophillia
  • Endocardial fibroelastosis
  • Endocardial neoplasms

Diagnosis

Signs and symptoms

Patients with RCM may be asymptomatic or present with symptoms of:

• angina
• cardiac failure: shortness of breath on exertion, orthopnoea, fatigue, paroxysmal nocturnal dyspnoea, abdominal discomfort, or leg swelling

Clinical signs that may be elicited on examination include: 

• bilateral basal crackles on lung auscultation
• hepatomegaly
• jugular venous distension
• peripheral oedema
• S3 gallop during rapid ventricular phase of diastole, indicating ventricular dilatation
• low pulse volume and faster pulse: in advanced phases

Other factors to consider in the history and examination include:

• Patients typically display signs and symptoms of heart failure with preserved ejection fraction (HFpEF)

• Carpal tunnel syndrome, lumbar spinal stenosis, aortic stenosis, skin bruising, proteinuria (cardiac amyloidosis)
• Erythema nodosum, lupus pernio (sarcoidosis)
• Bronze skin pigmentation, diabetes mellitus, arthralgia, chronic liver disease (haemochromatosis)
• Gait disturbance (Friedrich’s ataxia)
• Learning difficulties, visual impairment (Danon disease)
• Proteinuria, angiokeratoma, peripheral neuropathy (Anderson-Fabry disease)
• Three-generation family history 

Investigations

Table 3: Investigations for RCM

Management

Medical management 

• Broadly speaking, patients with symptomatic heart failure should be managed with loop diuretics for symptomatic relief and guideline-directed medical therapies (beta-blockers, ACEi/ARB/ARNi, MRA, SGLT2i). 
• However, caution should be exercised when using beta-blockers and ACEi/ARB/ARNi in patients with cardiac amyloidosis, as these drugs are poorly tolerated due to hypotension and autonomic dysfunction. Withdrawal of these drugs may help to improve symptoms. 
• All RCM patients with atrial fibrillation, in particular those with cardiac amyloidosis, should be started on oral anticoagulation irrespective of CHA2DS2-VA score due to a high risk of thromboembolism. 
• Disease-modifying treatment for specific RCM phenotypes are listed in Table 4. Patients with bradyarrhythmias may benefit from pacemaker implantation as per guidance from the European Society of Cardiology (ESC). 

Table 4: Selected RCM phenotypes and their respective disease-modifying therapies.

Surgical management

• Heart Transplantation
  • Heart transplantation may be considered in end-stage RCM patients with refractory heart failure and poor prognosis despite optimal medical therapy. 
  • Pulmonary vascular resistance study can be used to guide the timing of transplantation.
• ICDs
  • In select cases of RCM associated with severe ventricular arrhythmias or high risk of sudden cardiac death, ICDs may be considered for primary or secondary prevention.
  • Indicated in patients with sarcoidosis when a ventricular arrhythmia is detected

Complications

• Heart Failure
  • RCM is characterised by impaired ventricular filling due to restrictive physiology, leading to heart failure symptoms.
• Atrial Arrhythmias
  • RCM is associated with an increased risk of atrial arrhythmias, including atrial fibrillation, which can further impair cardiac function and increase the risk of thromboembolic events.
• Thromboembolism
  • Atrial arrhythmias and impaired ventricular function increase the risk of thrombus formation within the atria or ventricles, leading to thromboembolic events.
• Conduction Abnormalities
  • Fibrosis and infiltration of the myocardium can disrupt normal conduction pathways, leading to conduction abnormalities such as atrioventricular block or bundle branch block.