Primary restrictive cardiomyopathy is a rare form of cardiomyopathy that is characterized by normal or decreased ventricular volumes with bi-atrial enlargement, normal left ventricular wall thickness with impaired ventricular filling with restrictive physiology, and normal (or near normal) systolic function. Both sporadic and familial forms have been described. Restrictive Cardiomyopathy is characterized by abnormal diastolic filling or compliance with normal or decreased diastolic volume of the ventricular chamber with near normal or normal systolic function. Patients often require heart transplantation once symptomatic. In patients with familial inheritance its mode is autosomal recessive. Other etiologies include metabolic disease, carcinoid syndrome, hemosiderosis, amyloidosis, and secondary to radiation therapy.
On echocardiography, both ventricular cavities are typically small with decreased end diastolic dimensions. Marked bi-atrial enlargement is pathognomonic. Doppler echocardiography may demonstrate evidence of restrictive physiology (tricuspid and mitral valve inflow, pulmonary veins, tissue Doppler) and remains an important clinical tool to assess for evidence of diastolic dysfunction.
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