title: Relationship of surface electrogram recordings to activity in the underlying specialized conducting tissue.
mesh_terms: D000200:Action Potentials; D004562:Electrocardiography; D004566:Electrodes; D006329:Heart Conduction System / Q000503:physiopathology*; D006331:Heart Diseases / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008722:Methods