Cardiomyopathy describes a primary abnormality of the heart muscle. Heart failure (also known as congestive heart failure) is the syndrome of shortness of breath, fatigue, and swelling that people experience when they have a heart that doesn’t pump blood as well as it should – this can be from many reasons, including cardiomyopathy, or a past heart attack, or leaky heart valves. Over time, the heart often becomes too weak or stiff to fill and pump efficiently, resulting in death.