Cardiomyopathy describes any deterioration of function of the actual muscle tissue of the heart. It usually means the patient is at a high risk for arythmia or heart attack. It is most often caused by a reduction of blood flow to the heart.
It can be caused by several conditions, such as congenital heart disease, high blood pressure, alcoholism, diabetes mellitus, Chagas disease, anemia, sleep apnea, hyperthyroidism, haemochromatosis, and amyloidosis. However, it can also be caused by a heart attack.