title: A study in retrograde conduction.
mesh_terms: D001283:Atrioventricular Node / Q000503:physiopathology; D005117:Cardiac Complexes, Premature / Q000503:physiopathology; D004562:Electrocardiography; D006327:Heart Block / Q000503:physiopathology*; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans