Comparison of the effects of ipratropium bromide and salbutamol on autonomic heart rate control.
OBJECTIVE
B2-agonists and anticholinergic drugs may alter cardiac autonomic modulation. The aim of this study was to investigate the effects of inhaled salbutamol and ipratropium bromide on heart rate variability (HRV).


RESULTS
A randomized, double-blind, crossover design study was conducted on 13 healthy volunteers. Salbutamol, ipratropium or placebo was administered in three different testing sessions. Time domain parameters; mean R-R interval (mean-RR), the standard deviation of R-R interval (SDNN) and the root mean square of successive R-R interval differences (RMSSD) and power spectral analysis of HRV were assessed in the supine position and during handgrip exercise before and after taking each drug. In time domain analyses, ipratropium administration resulted in a reduced mean-RR, SDNN and RMSSD during handgrip exercise compared with baseline values (775 +/- 30 ms vs. 748 +/- 21 ms, P < 0.05; 57 +/- 5 ms vs. 50 +/- 5 ms, P < 0.05; 30 +/- 2 ms vs. 26 +/- 2 ms, P < 0.01, respectively). This effect was not detected with salbutamol or placebo administration. In frequency domain analyses, salbutamol but not ipratropium and placebo inhalation increased high frequency power/total power during handgrip exercise compared with baseline (0.09 +/- 0.02 vs. 0.12 +/- 0.02, P < 0.05).


CONCLUSIONS
Ipratropium inhalation may alter autonomic control of the heart rate in therapeutic doses during mild sympathetic stimulation in healthy subjects, while salbutamol does not show these effects.
Kaya
Dayimi
D
Department of Cardiology, Ege Saglik Hospital, Izmir, Turkey.
Barutcu
Irfan
I
Esen
Ali Metin
AM
Onrat
Ersel
E
Orman
Ayse
A
Unlu
Mehmet
M
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000328:Adult; D000420:Albuterol / Q000494:pharmacology*; D018680:Cholinergic Antagonists / Q000494:pharmacology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D009241:Ipratropium / Q000494:pharmacology*; D008297:Male
D000318:Adrenergic beta-Agonists; D018680:Cholinergic Antagonists; D009241:Ipratropium; D000420:Albuterol