Restrictive Cardiomyopathy (HCM)
In restrictive cardiomypathies the main problem is the inability of the ventricles to relax and expand during diastole. Thus there is restriction to the amount of blood that can enter the ventricle during this phase and consequently there is a smaller volume of blood ejected during systole. There are several disease that produce this "restrictive physiology" in the heart.
The most common in clinical practice is Cardiac Amyloidosis. Others include endomyocardial fibrosis (primary idiopathic or secondary to hypereosinophilia (in turn the eosinophilia can be primary (Loeffler's syndrome) or secondary to parasites), sarcodosis (which can also present as a dilated cardiomyopathy or as a myocarditis), progressive systemic sclerosis (scleroderma), carcinoid heart disease, and fibrosis secondary to radiation. Sarcoidosis Scleroderma Tumors of the heart