Acetylcholinesterase inhibition with pyridostigmine has been previously studied in patients with congestive heart failure (CHF), but the effects of this medication on heart rate recovery after exercise and other indices of parasympathetic activity in populations with greater baseline vagal tone has not been fully characterized. Ten healthy, sedentary adults and ten aerobically trained athletes were enrolled in a prospective, double blind, randomized placebo controlled crossover trial. All study subjects were treated with a single dose of oral pyridostigmine 30 mg and matching placebo on separate days. Heart rate variability (HRV) at rest and heart rate recovery (HRR) at one minute after maximal cardiopulmonary exercise stress testing were measured. In sedentary adults, pyridostigmine significantly lowered resting heart rate (mean (SEM) 58.1 (2.4) beats/min versus 66.7 (4.0) beats/min, p = 0.01), increased HRR at one minute (45.1 (2.8) beats/min versus 40.7 (3.4) beats/min, p = 0.02), and lowered both resting mean arterial pressure (80.3 (2.0) mm Hg versus 84.3 (2.7) mm Hg, p = 0.02) and peak exercise mean arterial pressure (103.3 (3.1) mm Hg versus 108.8 (3.2) mm Hg, p < 0.01). In trained athletes, resting heart rate and HRR at one minute were unaffected by pyridostigmine dosing, although a significant increase in VO2 max was observed with the study drug (54.8 (3.5) ml/kg/min versus 53.3 (3.6) ml/kg/min, p = 0.02). Pyridostigmine did not change indices of heart rate variability in either cohort. The difference in resting heart rate and HRR responses to pyridostigmine between athletes and sedentary controls likely reflects training induced modifications of the autonomic nervous system. The inability of acetylcholinesterase inhibition to affect HRV in either sedentary adults or athletes further suggests the improved HRR previously observed in CHF patients treated with pyridostigmine is secondary to parasympathetic augmentation.
| Identifer | oai:union.ndltd.org:YALE_med/oai:ymtdl.med.yale.edu:etd-06272006-104215 |
| Date | 10 November 2006 |
| Creators | Dewland, Thomas Andrew |
| Contributors | Stuart D Katz |
| Publisher | Yale University |
| Source Sets | Yale Medical student MD Thesis |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://ymtdl.med.yale.edu/theses/available/etd-06272006-104215/ |
| Rights | restricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Yale School of Medicine or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
Page generated in 0.0025 seconds