Restrictive cardiomyopathy is a relatively rare form of cardiomyopathy for which there are no uniform diagnostic criteria. The expert consensus on the definition and classification of cardiomyopathy published by the American Heart Association (AHA) in 2006 states that cardiomyopathy can be confined to the heart alone or be part of a systemic systemic disease, and if the lesion is confined to the myocardium only it is called primary cardiomyopathy, while secondary cardiomyopathy is defined as a lesion of the myocardium that is part of a systemic systemic disease. In this classification, restrictive cardiomyopathy is classified as primary cardiomyopathy, and both disseminated and familial cases have been reported. In the new classification of cardiomyopathies by the European Society of Cardiology (ESC) in 2008, restrictive cardiomyopathy was included as one of the five major categories of cardiomyopathies (the remaining four categories include hypertrophic cardiomyopathy, dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, and unclassified cardiomyopathy). Restrictive cardiomyopathy is a type of cardiomyopathy characterized by severely impaired diastolic function due to increased stiffness of the heart muscle. The systolic function of the patient’s heart is mostly normal or only mildly impaired, while diastolic function is mostly manifested as restrictive diastolic dysfunction. Ventricular restrictive filling abnormalities are manifested by an increase in myocardial stiffness that predisposes to a small increase in ventricular volume, i.e., an increase in ventricular pressure. Unlike other cardiomyopathies (e.g., hypertrophic cardiomyopathy, dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, and myocardial densification insufficiency), restrictive cardiomyopathy is a cardiomyopathy in which myocardial function is the main diagnostic criterion, and each of these cardiomyopathies has its own characteristic morphologic changes. In addition, restrictive diastolic dysfunction is also seen in many other diseases, such as dilated cardiomyopathy and advanced hypertrophic cardiomyopathy, so restrictive cardiomyopathy has been more difficult to define. Restrictive cardiomyopathy is only a descriptive diagnosis of a pathophysiological state and requires further analysis of the etiology.