Cardiomyopathy is a disease of the heart muscle that makes it difficult for the heart to pump blood effectively. There are three main types: dilated cardiomyopathy causes the heart chambers to enlarge; hypertrophic cardiomyopathy results in abnormal thickening of the heart muscle; and restrictive cardiomyopathy occurs when heart muscle is replaced with scar tissue causing stiffness. Symptoms include fatigue, shortness of breath, and heart failure. Treatment involves medications, surgically implanted devices, and possibly heart transplant for severe cases.