Cardiomyopathy IV: Restrictive Cardiomyopathy

Restrictive cardiomyopathy, or RCM, is characterized by impaired ventricular filling due to stiffened ventricular walls, leading to significant diastolic dysfunction.

RCM may develop idiopathically or as a result of systemic diseases.

For example, infiltrative diseases like amyloidosis cause RCM through amyloid deposits between cardiomyocytes, while storage diseases such as hemochromatosis result from iron deposits in the heart and cause stiffness.

The pathophysiology of RCM involves reduced ventricular compliance due to fibrosis or infiltration by substances like amyloid proteins, which impairs ventricular relaxation and increases stiffness.

This stiffening of the ventricular walls increases filling pressures and impairs diastolic filling.

As a result, cardiac output decreases, and pulmonary venous pressures rise, causing pulmonary congestion and heart failure symptoms.

Next, clinical manifestations of RCM include fatigue, exercise intolerance, dyspnea, angina, orthopnea, and palpitations.

Lastly, diagnosing RCM involves echocardiography to assess diastolic function and wall size and cardiac MRI to identify specific infiltrative or fibrotic processes.