Comparison of the short-term effects of salmeterol and formoterol on heart rate variability in adult asthmatic patients.

STUDY

OBJECTIVES

We investigated the effects of beta2-adrenergic agonists salmeterol and formoterol on heart rate variability (HRV) in adult asthmatic patients using time-domain measures of HRV.

PATIENTS: Thirty-nine adult patients with asthma were studied. All patients showed a mild-to-moderate decrease in baseline FEV1. Any diseases that might have influenced the autonomic function were excluded. All patients underwent a complete physical examination and medical history that revealed no cardiovascular disease or medication.

METHODS

The beta2-adrenergic inhaled agonists salmeterol, 50 microg, and formoterol, 12 microg, were used in the study. HRV analysis was performed for each 5-min segment: 5 min and 10 min before inhalation of the study drug, and 5, 10, 15, 20, 25, and 30 min after inhalation. Time-domain parameters of HRV were calculated: (1) the SD all normal-to-normal intervals; (2) the SD of the mean of all normal-to-normal intervals in all 5-min segments of the entire recording; (3) the root mean square of differences between adjacent normal-to-normal intervals; (4) the mean of the SD of all normal-to-normal intervals in all the 5-min intervals; and (5) the SD of the SD of all normal-to-normal intervals in all the 5-min intervals.

RESULTS

Baseline HRV parameters were not significantly different between formoterol and salmeterol groups. There were no significant differences in HRV parameters after formoterol and salmeterol inhalation. The HRV parameters in each 5-min segment in the formoterol group were not statistically significant different when compared to the same segment in the salmeterol group.

CONCLUSION

Salmeterol and formoterol have no short-term adverse effects on HRV.