title: Physiologic and biologic variants of the electrocardiogram.
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging; D001145:Arrhythmias, Cardiac / Q000139:chemically induced / Q000503:physiopathology*; D001919:Bradycardia / Q000503:physiopathology; D002037:Bundle-Branch Block / Q000503:physiopathology; D003937:Diagnosis, Differential; D004562:Electrocardiography; D005260:Female; D006321:Heart / Q000502:physiology*; D006327:Heart Block / Q000503:physiopathology; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000503:physiopathology; D005082:Physical Exertion; D013178:Sports Medicine; D013577:Syndrome; D013610:Tachycardia / Q000503:physiopathology