Cardiomyopathy means "disease of the heart muscle". There are three different types: restrictive, dilated, and hypertrophic. All three different types share the common end result of heart failure and severe cases of all three can only be treated with a heart transplant.
In restrictive cardiomyopathy the walls of the left and right ventricle and the septum become very rigid as a result of scar tissue or some other material such as iron or protein which has gotten into the muscle. The rigidity of the muscle does not allow the ventricles to fill properly which causes a raised back pressure in the veins. As a result, the symptoms include swollen ankles, enlargement of the liver and accumulation of fluid in the abdomen and lungs.
Dilated cardiomyopathy is a condition in which the ventricles of the heart become too large. The ventricles do not contract with as much strength and cardiac output is greatly diminished. Most cases of dilated cardiomyopathy result in heart failure. Overindulgence in alcohol one of the leading causes of dilated cardiomyopathy.
In hypertrophic cardiomyopathy parts of the heart muscle (more specifically the left ventricular wall and the septum) become abnormally large and thick. This disease often has no symptoms and there is no obvious underlying cause. Many times the first sign of the defect is simply death. 50% or more of all cases of hyperthrophic cardiomyopathy have genetic causes.