Mitochondrial encephalomyopathy (Kearns-Sayre syndrome) with complete atrioventricular block: a case report

A pacemaker was implanted into a 17-year-old man with cardiac failure due to complete atrioventricular block complicated by mitochondrial encephalomyopathy (Kearns-Sayre syndrome). Due to the possible complication of latent myocardial dysfunction, it was decided to implant the dual chamber pacemaker (DDD) and the operation mode was set to DDD 70 ppm 1 year after implantation; this alleviated the cardiac failure. In this case, the necessity of preventive pacemaker implantation in the early stage of cardiac failure was recognized.