Ventricular arrhythmia revealing mitochondrial myopathy in a 69-year-old woman.

We report a case of mitochondrial myopathy (MM), assessed by histological and biochemical studies. This illness was diagnosed in a 69-year-old patient with myocardiopathy revealed by ventricular arrhythmias. The originality of this case lies in the patient's age, the mode of onset and the biochemical features (i.e. normal mitochondrial enzymatic complexes but very low respiration when using glutamate as a substrate).