title: Cholinergic stimulation with pyridostigmine reduces the QTc interval in coronary artery disease.
abstract: Parasympathetic dysfunction is an independent risk factor in patients with coronary artery disease; thus, cholinergic stimulation is a potential therapeutic measure that may be protective by acting on ventricular repolarization. The purpose of the present study was to determine the effects of pyridostigmine bromide (PYR), a reversible anticholinesterase agent, on the electrocardiographic variables, particularly QTc interval, in patients with stable coronary artery disease. In a randomized double-blind crossover placebo-controlled study, simultaneous 12-lead electrocardiographic tracings were obtained at rest from 10 patients with exercise-induced myocardial ischemia before and 2 h after the oral administration of 45 mg PYR or placebo. PYR increased the RR intervals (pre: 921 +/- 27 ms vs post: 1127 +/- 37 ms; P<0.01) and, in contrast with placebo, decreased the QTc interval (pre: 401 +/- 3 ms vs post: 382 +/- 3 ms; P<0.01). No other electrocardiographic variables were modified (PR segment, QT interval, QT and QTc dispersions). Cholinergic stimulation with PYR caused bradycardia and reduced the QTc interval without important side effects in patients with coronary disease. These effects, if confirmed in studies over longer periods of administration, may suggest a cardioprotection by cholinergic stimulation with PYR.
authors.affiliation: Departamento de Fisiologia e Farmacologia, Universidade Federal Fluminense, Niterói, RJ, Brasil.
authors.forename: R R T
authors.initials: RR
authors.lastname: Castro
authors.forename: G
authors.initials: G
authors.lastname: Porphirio
authors.forename: S M
authors.initials: SM
authors.lastname: Serra
authors.forename: A C L
authors.initials: AC
authors.lastname: Nóbrega
mesh_terms: D000704:Analysis of Variance; D001919:Bradycardia / Q000139:chemically induced; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D003327:Coronary Disease / Q000503:physiopathology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004562:Electrocardiography / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008875:Middle Aged; D011729:Pyridostigmine Bromide / Q000494:pharmacology*
chemical_list: D002800:Cholinesterase Inhibitors; D011729:Pyridostigmine Bromide