– Shows usually concentric left ventricular hypertrophy
Hypertrophic cardiomyopathy. This type involves abnormal thickening of the heart muscle, which makes it harder for the heart to work. It mostly affects the muscle of the heart's main pumping chamber (left ventricle).
Hypertrophic cardiomyopathy can develop at any age, but the condition tends to be more severe if it occurs during childhood. Most people with this type of cardiomyopathy have a family history of the disease. Some genetic changes have been linked to hypertrophic cardiomyopathy.
Dilated cardiomyopathy. In this type of cardiomyopathy, the heart's main pumping chamber — the left ventricle — becomes enlarged (dilated) and can't effectively pump blood out of the heart.
Although this type can affect people of all ages, it occurs most often in middle-aged people and is more likely to affect men. The most common cause is coronary artery disease or heart attack. However, it can also be caused by genetic changes.
Restrictive cardiomyopathy. In this type, the heart muscle becomes stiff and less flexible, so it can't expand and fill with blood between heartbeats. This least common type of cardiomyopathy can occur at any age, but it most often affects older people.
Restrictive cardiomyopathy can occur for no known reason (idiopathic), or it can by caused by a disease elsewhere in the body that affects the heart, such as amyloidosis.
Myocarditis
♦ “Dallas criteria”: leukocytic infiltrate (usually lympho_x0002_cytic) with myocyte degeneration/necrosis
Clinical
♦ Viral (most often coxsackievirus B), bacterial, fungal, para_x0002_sitic, collagen-vascular disease, drug reaction, radiation
