Arrhythmogenic cardiomyopathy

Arrhythmogenic cardiomyopathy, or ACM, is an inherited heart disease. It is caused by genetic defects in the desmosomes, the structures on the surface of cardiac muscle cells that link them together, and many of the proteins that make up desmosomes can carry harmful mutations. It is a non-ischemic cardiomyopathy that mainly involves the right ventricle, though cases confined to the left ventricle occur, and it is characterized by weak areas of the ventricular wall where muscle is replaced by fibrous and fatty tissue, with rhythm disturbances that often start in the right ventricle. The older name arrhythmogenic right ventricular dysplasia is now considered misleading. ACM is an important cause of ventricular arrhythmias in children and young adults, is seen mostly in males, and runs in families in 30 to 50 percent of cases. In the recessive Naxos disease it accompanies thickened skin of the palms and soles and woolly hair.