Restrictive cardiomyopathy is a condition where your ventricles do not thicken, yet they still become stiff and rigid and cannot pump blood effectively.

In this type of cardiomyopathy, the pumping ability of your heart’s main pumping chamber — the left ventricle — becomes enlarged (dilated) and can’t effectively pump blood out of the heart.

This type involves abnormal thickening of your heart muscle, which makes it harder for the heart to work. It mostly affects the muscle of your heart’s main pumping chamber (left ventricle).

In this rare type of cardiomyopathy, the muscle in the lower right heart chamber (right ventricle) is replaced by scar tissue, which can lead to heart rhythm problems. It’s often caused by genetic mutations.