Chronic atrial fibrillation associated with somatic mitochondrial DNA mutations in human atrial tissue

2, 3 However, these studies only checked mtDNA deletion in atrial tissue and did not examine the corresponding blood samples. [...]we analysed the mtDNA control region and cytochrome c oxidase (CO) I, COII, COIII, ATPase 6 and cytochrome b (Cytb) genes in matched atrial tissues and blood samples from patients with cAF and in two matched patients with normal sinus rhythm and no history of cAF. Sequence chromatogram of two tandem copies of the 9 bp motif (ACCCCCTCT), located in the non-coding region V (nucleotides 8271-8288) between the cytochrome oxidase II (COII) and tRNA lysine (tRNAlys) genes (D, right).\n Oxidative injury and deletion of mtDNA in cardiac muscle are increased in patients with cAF, which may contribute to the impairment of the bioenergetic function of mitochondria and induction of the oxidative vicious cycle involved in the pathogenesis of atrial myopathy in cAF. 1 In progressive external ophthalmoplegia syndrome and Kearns-Sayre syndrome, which both present with cardiomyopathy, mtDNA 4977 bp deletions are extensively present in the myocardium., right).