Short-term effects of inhaled salbutamol on autonomic cardiovascular control in healthy subjects: a placebo-controlled study

摘要

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT ? Previous reports have demonstrated a link between inhaled β ₂ -agonist use and cardiovascular morbidity and mortality. ? The underlying mechanism for this relationship, however, remains controversial. WHAT THIS STUDY ADDS ? Inhalation of a therapeutic dose of salbutamol resulted in significant haemodynamic changes, which were accompanied by a shift in cardiovascular autonomic tone towards increased sympathetic outflow in the absence of baroreceptor activation. ? The observed changes in cardiac autonomic function may contribute to an increased cardiac risk associated with inhaled β ₂ -agonist treatment. AIMS To investigate short-term effects of inhaled salbutamol on haemodynamic changes and cardiovascular autonomic control. METHODS A randomized, single-blinded, placebo-controlled study of 0.2 mg of inhaled salbutamol was conducted on 12 healthy nonsmoking volunteers with a mean age of 24 ± 2 years at two different testing sessions. Non-invasively obtained continuous haemodynamic measurements of cardiac output, beat-to-beat arterial blood pressure, and total peripheral resistance were recorded prior to and for a total of 120 min after inhalation of the respective study drug. Continuous cardiovascular autonomic tone was recorded using power spectral analysis of heart rate and blood pressure variability. Spontaneous baroreceptor activity was assessed by the sequence method. RESULTS There were no significant changes in any of the baseline parameters between the different testing sessions. Inhalation of salbutamol caused a significant increase in cardiac output from 6.7 ± 1.3 to 7.7 ± 1.4 l min ^?1 ( P ?1 cm ^?5 ( P CONCLUSIONS Inhalation of therapeutic doses of salbutamol in healthy subjects resulted in significant haemodynamic changes and a shift of sympathovagal balance towards increased sympathetic tone in the absence of baroreceptor activation.