Cardiological manifestations of mitochondrial respiratory chain disorders.

Mitochondrial Respiratory Chain Disorders (MRCD) are a heterogeneous group of disorders that share the involvement of the cellular bioenergetic machinery due to molecular defects affecting the mitochondrial oxidative phosphorylation system (OXPHOS). Clinically, they usually involve multiple tissues although they tend to mainly affect nervous system and skeletal muscle. Cardiological manifestations are frequent and include hypertrophic or dilated cardiomyopathies and heart conduction defects, being part of adult or infantile multisystemic mitochondrial disorders or, less frequently, presenting as isolated clinical condition. The aim of this review is to update the cardiological manifestations in both adult and infantile mitochondrial disorders going briefly over mitochondrial genetics. Cardiac involvement is a common feature associated with early and late onset forms of MRCD. In particular cases, these conditions should be considered into the diagnostic algorithm of idiopathic cardiomyopathies. Physicians strictly related with this disorders need to be aware of heart complications and therefore periodical cardiological examinations should be performed in such patients. Finally, therapeutic strategies are suggested to treat cardiac disorders in MRCD