The sick sinus syndrome.
D001146:Arrhythmia, Sinus; D001281:Atrial Fibrillation / Q000503:physiopathology; D001341:Autonomic Nervous System / Q000503:physiopathology; D001919:Bradycardia / Q000503:physiopathology*; D002036:Bundle of His / Q000503:physiopathology; D004562:Electrocardiography; D004702:Endocrine Glands / Q000503:physiopathology; D005080:Exercise Test; D006801:Humans; D012849:Sinoatrial Node / Q000503:physiopathology*; D013575:Syncope; D013577:Syndrome