Mitochondrial diseases: what the cardiologist should know?

Mitochondrial diseases (MD) are a heterogeneous group of rare genetically determined disorders, characterized by mitochondrial respiratory chain defect and subsequent energy metabolism imbalance. Due to almost exclusive aerobic metabolism of the heart, cardiac involvement in MD is common and can be accompanied by other manifestations of the multi-organ involvement, but may be also the first or the sole clinical manifestation of MD. All tissues of the heart may be affected but the most frequently affected tissue is the myocardium. The most frequent cardiac manifestation found in MD are cardiomyopathies, but cardiac abnormalities may be varied and include arrhythmias, heart failure, pulmonary hypertension, aortic root dilation, and pericardial effusion. Given the progressive nature of cardiac involvement in MD, its association with poor prognosis and increased mortality, and the fact that it can remain asymptomatic until an advanced stage is reached, often due to limited patient mobility, cardiac screening should be a part of standard management of MD patients. All patients with cardiac involvement should be reviewed by a cardiologist with an expertise in the management of such patients