The sick sinus syndrome.
D000200:Action Potentials; D000368:Aged; D001146:Arrhythmia, Sinus / Q000175:diagnosis / Q000503:physiopathology*; D001919:Bradycardia / Q000503:physiopathology*; D003326:Coronary Circulation; D003327:Coronary Disease / Q000150:complications; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria / Q000503:physiopathology; D006327:Heart Block / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000503:physiopathology; D012848:Sinoatrial Block / Q000503:physiopathology*; D012849:Sinoatrial Node / Q000503:physiopathology; D009435:Synaptic Transmission; D013577:Syndrome; D013610:Tachycardia / Q000503:physiopathology