[Restrictive cardiomyopathy].

Restrictive cardiomyopathies are the rarest forms of cardiomyopathy. They are characterised by restrictive filling and reduction in diastolic volume of one or both ventricles with normal wall thickness and systolic function. Increased interstitial fibrosis may be observed. This form of cardiomyopathy may be idiopathic or associated with other conditions (amyloid disease, endomyocardial pathology with or without hypereosinophilia). The idiopathic variety is sometimes familial. The symptoms are not specific except for angina in cases of amylosis. All the signs of cardiac failure except cardiomegaly are present in advanced stages. In the idiopathic forms, thromboembolic complications are common. Atrial fibrillation and atrioventricular block are also often observed. The differential diagnosis with chronic constrictive pericarditis is sometimes difficult. Different investigations (Doppler echocardiography, CT scan, magnetic resonance imaging, isotopes, cardiac catheterisation and endomyocardial biopsy) may all fail to make the diagnosis and pericardectomy may have to be performed in the last resort. Treatment is based on diuretics, prevention of atrial fibrillation (amiodarone) and oral anticoagulants. Digoxin, which fixes to amyloid fibrils, may be arrhythmogenic in amyloidosis. Cardiac pacing may be used in cases of atrioventricular block and brady-arrhythmias. Cardiac transplantation is available in advanced forms after exclusion of amyloidosis. New specific therapeutic approaches to amyloidosis are discussed.