title: Sick sinus node syndrome.
mesh_terms: D000368:Aged; D001146:Arrhythmia, Sinus / Q000175:diagnosis* / Q000503:physiopathology; D001285:Atropine; D005117:Cardiac Complexes, Premature / Q000209:etiology; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria; D006329:Heart Conduction System / Q000503:physiopathology; D006339:Heart Rate; D006801:Humans; D007545:Isoproterenol; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D005082:Physical Exertion; D013610:Tachycardia / Q000209:etiology
chemical_list: D001285:Atropine; D007545:Isoproterenol