Cardiac manifestations of primary mitochondrial disorders

- Cardiac involvement in mitochondrial disorders is frequent but more variable and comprehensive than previously thought.
- Cardiac involvement in mitochondrial disorders may be classified as structural or functional, primary or secondary.
- All tissues of the heart may be variably affected but the most frequently affected tissue is the myocardium.
- Cardiac involvement in mitochondrial disorders occurs in syndromic as well non-syndromic cases.
- Any cardiac disease of unknown cause can represent a MID why they are differential diagnoses of cardiac disease.

ObjectivesOne of the most frequently affected organs in mitochondrial disorders (MIDs), defined as hereditary diseases due to affection of the mitochondrial energy metabolism, is the heart. Cardiac involvement (CI) in MIDs has therapeutic and prognostic implications. This review aims at summarizing and discussing the various cardiac manifestations in MIDs.MethodsData for this review were identified by searches of MEDLINE, Current Contents, and PubMed using appropriate search terms.ResultsCI in MIDs may be classified according to various different criteria. In the present review cardiac abnormalities in MIDs are discussed according to their frequency with which they occur. CI in MIDs includes cardiomyopathy, arrhythmias, heart failure, pulmonary hypertension, dilation of the aortic root, pericardial effusion, coronary heart disease, autonomous nervous system dysfunction, congenital heart defects, or sudden cardiac death. The most frequent among the cardiomyopathies is hypertrophic cardiomyopathy, followed by dilated cardiomyopathy, and noncompaction.ConclusionsCI in MID is more variable and prevalent than previously thought. All tissues of the heart may be variably affected. The most frequently affected tissue is the myocardium. MIDs should be included in the differential diagnoses of cardiac disease.