Abstract
Sinus node dysfunction, previously unreported in girls, occurred in a 13-year-old girl who required permanent pacemaker implantation because of recurrent syncopal attacks. In addition to periodic sinus arrest, the presence of significant atrioventricular conduction disturbance was also documented. Although she had had a persistent ductus arteriosus divided at an earlier age, the disturbance of rhythm and conduction cannot be ascribed to a congenitial or haemodynamic abnormality. An acquired origin can only be postulated.