Mitochondrial cardiomyopathies: navigating through different clinical and management pictures between adult and paediatric forms.

Mitochondrial diseases (MD) represent a group of rare disease with an estimated prevalence of 5-12 per 100,000 individuals, with a prevalence at birth of 1:5,000 and with childhood-onset of 5-15 per 10,000. They are characterized by a multisystemic phenotype with neurodegenerative, neuromuscular, ophthalmological, endocrinological, gastroenterological and cardiac manifestations. MD can present as a systemic disease or with single organ involvement. When cardiac involvement is the presenting feature, physicians must have a high level of suspicion to search for other organ involvement that can lead to the diagnosis. Cardiovascular manifestations are frequently reported in MD with a significant contribute to mortality. Cardiac involvement is particularly represented in MD with an estimated incidence of 20%-40% in children. Presentation is manifesting as a wide range of cardiac disease, encompassing cardiomyopathy, disturbance of conduction systems, aortopathy and pulmonary hypertension. The aim of this review is to provide a cardiological perspective on the cardiac involvement occurring in the main MD, according to the age of onset, clinical and phenotypic presentation, focusing on the paediatric and adult differences.