The long-term increase of baseline and reflexly augmented levels of human vagal-cardiac nervous activity induced by scopolamine.
We tested the hypothesis that transdermal scopolamine increases vagal-cardiac nervous outflow over the long term in 16 healthy young men. Twenty-four hours after application of one scopolamine patch, the average RR interval was increased by 13% and the average standard deviation of the RR interval (taken as an index of the level of vagal-cardiac nervous activity) was increased by 31%. Baroreceptor-cardiac reflex responsiveness (as reflected by prolongation of RR interval provoked by graded neck suction) also was increased substantially. These findings suggest that vagal-cardiac nervous activity can be augmented pharmacologically in man on a long-term basis. Since vagal outflow influences cardiac electrical properties in an important way, these findings may have therapeutic implications.
D000328:Adult; D001145:Arrhythmias, Cardiac / Q000139:chemically induced; D004305:Dose-Response Relationship, Drug; D004562:Electrocardiography; D006329:Heart Conduction System / Q000187:drug effects*; D006801:Humans; D008297:Male; D012018:Reflex / Q000187:drug effects*; D012601:Scopolamine / Q000009:adverse effects / Q000097:blood / Q000494:pharmacology*; D013997:Time Factors; D014630:Vagus Nerve / Q000187:drug effects*
D012601:Scopolamine