Patients with restrictive cardiomyopathy have a poor prognosis. In pediatric patients, the disease often worsens progressively, with a survival rate of only 50% at 2 years after diagnosis. Arrhythmias, strokes, and even sudden death can occur even when patients do not have severe symptoms of heart failure. Pre-existing chest pain or syncope is a risk factor for sudden death, independent of the presence of heart failure symptoms. In another study on the prognosis of adults with restrictive cardiomyopathy, 50% of patients died during a mean follow-up of 68 months, and 68% of those who died died from cardiovascular factors, with male, age, cardiac function and anterior-posterior left atrial diameter >60 mm being independent risk factors for death. It should be noted that in 1 4-year follow-up of patients with restrictive cardiomyopathy in children, sudden death occurred in 28% of patients, much higher than in dilated cardiomyopathy (11%) and comparable to hypertrophic cardiomyopathy (3l%).