Cardiac Involvement in Mitochondrial Disorders

Abstract

Purpose of review: We review pathophysiology and clinical features of mitochondrial disorders manifesting with cardiomyopathy.

Recent findings: Mechanistic studies have shed light into the underpinnings of mitochondrial disorders, providing novel insights into mitochondrial physiology and identifying new therapeutic targets. Mitochondrial disorders are a group of rare genetic diseases that are caused by mutations in mitochondrial DNA (mtDNA) or in nuclear genes that are essential to mitochondrial function. The clinical picture is extremely heterogeneous, the onset can occur at any age, and virtually, any organ or tissue can be involved. Since the heart relies primarily on mitochondrial oxidative metabolism to fuel contraction and relaxation, cardiac involvement is common in mitochondrial disorders and often represents a major determinant of their prognosis.

Keywords: Cardiolipin; Cardiomyopathy; Electron transport chain; Mitochondrial DNA; Mitochondrial disease.

Fig. 1

Mechanisms of mitochondrial dysfunction in inherited mitochondrial disorders. Created with BioRender.com. Abbreviations: AGK, acylglycerol kinase; ANT1, adenine nucleotide translocator 1; CACT, carnitine-acylcarnitine translocase; CL, cardiolipin; CPT1/2, carnitine palmitoyltransferase 1/2; DCMA, dilated cardiomyopahty with ataxia; ETC, electron transport chain; FA-CoA, fatty acyl-CoA; FXN, frataxin; LHON, Leber’s hereditary optic neuropathy; OXPHOS, oxidative phosphorylation; TAZ, tafazzin

Fig. 2

Defects in cardiac excitation–contraction coupling and cellular calcium handling in Barth syndrome. Created with BioRender.com. Abbreviations: ETC, electron transport chain; MCU, mitochondrial calcium uniporter; TAZ, tafazzin