title: Familial sinoatrial node dysfunction. Increased vagal tone a possible aetiology.
abstract: Clinical and electrophysiological studies of a 13-year-old boy with sinus bradycardia revealed sinus node dysfunction. Long-term follow-up data of members of his family indicated familial sinus node dysfucntion. Increased vagal tone was present in all patients. It is suggested that excessive vagal discharge for a pronlonged time may be the basic mechanism of sinus node dysfunction in these patients.
mesh_terms: D000293:Adolescent; D000328:Adult; D001919:Bradycardia / Q000209:etiology; D005260:Female; D006331:Heart Diseases / Q000235:genetics / Q000503:physiopathology; D006801:Humans; D008297:Male; D010375:Pedigree; D012849:Sinoatrial Node / Q000503:physiopathology; D014630:Vagus Nerve / Q000503:physiopathology*