title: Sick sinus syndrome in a patient with familial PR prolongation.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001146:Arrhythmia, Sinus / Q000150:complications / Q000503:physiopathology*; D001919:Bradycardia / Q000150:complications / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D004562:Electrocardiography; D005260:Female; D006327:Heart Block / Q000150:complications / Q000235:genetics / Q000503:physiopathology; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012849:Sinoatrial Node; D013577:Syndrome