Risk factors. People of all ages are subject to cardiomyopathy. Risk factors include diabetes, coronary heart disease, severe obesity, and a family history of heart failure or heart attack. Sarcoidosis causes granulomas to grow in the body as a possible immune response to unknown causes. Heart granulomas lead to cardiomyopathy. Amyloidosis causes random deposits of an abnormal protein called amyloid which is produced in bone marrow. This condition can cause the heart to pump less blood per beat which can cause shortness of breath. If the electrical system of the heart is affected, heart rhythm will become abnormal. Hemochromatosis leads to excess iron absorption from foods. This iron is stored in body organs such as the pancreas, liver, and heart and can lead to life-threatening conditions.