What condition is characterized by lower chambers of the heart that are rigid and do not expand as ventricles fill with blood?

Restrictive Cardiomyopathy is characterized by the stiffness of the heart walls, particularly in the lower chambers (ventricles), which limits their ability to expand and fill adequately with blood during the diastolic phase of the heartbeat. This condition usually results from the walls of the ventricles becoming severely fibrotic or infiltrated with abnormal substances, leading to impaired diastolic filling and heart failure symptoms.

Patients with Restrictive Cardiomyopathy often experience symptoms such as shortness of breath, fatigue, and swelling in the legs due to fluid retention, as the heart cannot properly accommodate returning blood. Unlike other forms of cardiomyopathy, the ejection fraction may remain normal in the early stages, but overall cardiac output becomes compromised due to the reduced filling capacity of the ventricles.

Understanding the distinct nature of Restrictive Cardiomyopathy helps in differentiating it from other cardiomyopathy types, such as Hypertrophic Cardiomyopathy, which is characterized by thickened heart muscle that can obstruct blood flow, and Dilated Cardiomyopathy, where the heart chambers are dilated and weaker. Arrhythmogenic Cardiomyopathy involves the replacement of cardiac muscle with fibrous or fatty tissue, leading to electrical issues but does not primarily involve rigid ventricles.