title: The sick sinus syndrome: natural history of dysfunction of the sinoatrial node.
mesh_terms: D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000503:physiopathology*; D001281:Atrial Fibrillation / Q000503:physiopathology; D001919:Bradycardia / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D012848:Sinoatrial Block / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D012849:Sinoatrial Node / Q000503:physiopathology*; D013997:Time Factors