| Feature | Details |
|---|---|
Ventricular involvement | The left ventricle and often the right ventricle show dilatation and impaired contraction. |
Left ventricular structure | Mass is increased, while wall thickness is normal or reduced. |
Valve dysfunction | Dilatation of the valve rings can cause functional mitral and tricuspid incompetence. |
Histology | Changes are variable and include myofibrillary loss, interstitial fibrosis and T-cell infiltrates. |
| Feature | Details |
|---|---|
Inheritance | At least 25% of cases are inherited as an autosomal dominant trait, and various single-gene mutations have been identified. |
Affected proteins | Most mutations affect proteins in the myocyte cytoskeleton. Examples listed include dystrophin, lamin A and C, emerin and metavinculin. |
Skeletal muscle abnormalities | Many mutations are also associated with abnormalities of skeletal muscle. |
Muscular dystrophies | The X-linked skeletal muscular dystrophies Becker and Duchenne are also associated with cardiomyopathy. |
| Feature | Details |
|---|---|
Alcohol | Alcohol may be an important cause in some patients. |
Post-myocarditis mechanism | A late autoimmune reaction to viral myocarditis is thought to cause dilated cardiomyopathy in a substantial subgroup. |
Advanced HIV infection | A similar mechanism is believed to account for myocardial involvement, which occurs in up to 10% of patients with advanced human immunodeficiency virus infection. |