The sick sinus.
D001146:Arrhythmia, Sinus / Q000175:diagnosis; D001145:Arrhythmias, Cardiac / Q000145:classification; D001281:Atrial Fibrillation; D001919:Bradycardia / Q000175:diagnosis; D002560:Cerebrovascular Circulation; D006323:Heart Arrest / Q000175:diagnosis; D006333:Heart Failure; D006801:Humans; D011379:Prognosis; D012849:Sinoatrial Node / Q000503:physiopathology; D013312:Stress, Physiological; D013577:Syndrome; D013610:Tachycardia / Q000175:diagnosis