Indications for pacemaker implantation in the Kearns-Sayre syndrome.

The Kearns-Sayre syndrome is a rare condition, characterized by progressive external ophthalmoplegia, retinal pigmentary degeneration and progressive impairment of cardiac conduction, which mainly determines the prognosis. Two young patients (aged 13 and 18 years) without symptoms of cardiac disease presented with an electrocardiogram showing sinus rhythm, a normal atrio-ventricular conduction time, right bundle branch block and a left anterior fascicular block. Electrophysiologic investigation showed prolongation of His-ventricular interval at rest, which further increased during atrial pacing. Because of the potential progression of the conduction abnormalities and threatening sudden death, we decided to implant a pacemaker in both patients. Ten months later one patient had become pacemaker-dependent. Prophylactic pacemaker therapy is advisable in patients suffering from the Kearns-Sayre syndrome, who have bifascicular block on the precordial electrocardiogram.