title: Electrophysiology of atropine.
abstract: The effect of atropine on the refractory periods of the human atrium, A-V node, and His-Purkinje system was studied. The A-V node in man appears more sensitive to atropine than the atria as evidenced by a reduction in the effective and functional refractory periods of the A-V node without alteration of atrial conduction. Although atropine does not directly alter the refractory periods of the His-Purkinje system, atropine-induced facilitation of A-V nodal conduction results in block of premature atrial impulses in the His-Purkinje system, demonstrating an indirect effect of atropine on His-Purkinje conduction. Rarely, atropine may precipitate re-entrant atrial tachycardia (one patient) through facilitation of A-V nodal conduction.
mesh_terms: D000328:Adult; D000368:Aged; D001283:Atrioventricular Node / Q000187:drug effects; D001285:Atropine / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use; D002036:Bundle of His / Q000187:drug effects; D002037:Bundle-Branch Block / Q000139:chemically induced; D006328:Cardiac Catheterization; D004562:Electrocardiography; D004594:Electrophysiology; D006321:Heart / Q000187:drug effects*; D006325:Heart Atria / Q000187:drug effects; D006329:Heart Conduction System / Q000187:drug effects*; D006331:Heart Diseases / Q000188:drug therapy; D006801:Humans; D006852:Hydrochlorothiazide / Q000627:therapeutic use; D006973:Hypertension / Q000188:drug therapy; D008750:Methyldopa / Q000627:therapeutic use; D008875:Middle Aged; D009431:Neural Conduction / Q000187:drug effects*; D005996:Nitroglycerin / Q000627:therapeutic use; D011690:Purkinje Fibers / Q000187:drug effects; D012032:Refractory Period, Electrophysiological / Q000187:drug effects*; D012214:Rheumatic Heart Disease / Q000188:drug therapy; D013610:Tachycardia / Q000139:chemically induced
chemical_list: D006852:Hydrochlorothiazide; D008750:Methyldopa; D001285:Atropine; D005996:Nitroglycerin