title: His bundle electrograms in healthy adolescents with persistent second degree A-V block.
mesh_terms: D000293:Adolescent; D000328:Adult; D001285:Atropine / Q000494:pharmacology; D004562:Electrocardiography; D005080:Exercise Test; D006327:Heart Block / Q000503:physiopathology*; D006329:Heart Conduction System / Q000187:drug effects / Q000503:physiopathology*; D006801:Humans; D008297:Male
chemical_list: D001285:Atropine