Effects of different doses of dexmedetomidine on heart rate variability in patients with non-ST-segment elevation myocardial infarction / 中国医师进修杂志

ABSTRACT

Objective:To investigate the effects of different doses of dexmedetomidine (Dex) on heart rate variability (HRV) in patients with non-ST-segment elevation myocardial infarction (NSTEMI).Methods:The clinical data of 144 patients with NSTEMI from January 2017 to October 2020 in the 942 Hospital of Chinese PLA were analyzed retrospectively. Among them, 36 cases were treated with Dex 0.05 to 0.15 μg/(kg·h) (Dex1 group), 36 cases with Dex 0.20 to 0.40 μg/(kg·h) (Dex2 group), 36 cases with Dex 0.50 to 0.70 μg/(kg·h) (Dex3 group), and 36 cases without Dex (control group). The changes of HRV time domain indexes, frequency domain indexes and prognosis index before and after treatment were compared among 4 groups, the time domain indexes include normal R-R interval standard deviation (SDNN), mean value of adjacent normal R-R interval standard deviation (SDANNindex), root mean square of adjacent normal R-R interval standard deviation (SDNNindex), square root of adjacent normal R-R interval difference (rMSSD) and percentage of adjacent normal R-R interval difference>50 ms to R-R interval number (PNN50); the frequency domain indexes include total power (TP), low frequency power (LF), high frequency power (HF), ultra-low frequency power (VLF) and LF/HF; the prognostic indexes include ICU stay time, vasoactive drug use time, 28-day mortality and incidence of complication.Results:There was no significant difference in HRV indexes among 4 groups before treatment ( P>0.05); after treatment, except for LF/HF in Dex2 group and Dex3 group was significantly lower than that in control group and Dex1 group, other HRV indexes were significantly higher than those in control group and Dex1 group, and there were statistical differences ( P<0.05). There was no significant difference in 28-day mortality among 4 groups; the ICU stay time and vasoactive drug use time in Dex2 group were significantly shorter than those in control group, Dex1 group and Dex3 group (7.14 ± 1.25) d vs. (9.08 ± 1.68), (9.53 ± 1.98) and (9.81 ± 1.95) d, (122.67 ± 29.5) h vs. (176.15 ± 23.26), (181.72 ± 23.40) and (180.42 ± 22.90) h, the incidence of complication was significantly lower than that in control group, Dex1 group and Dex3 group 16.67% (6/36) vs. 72.22% (26/36), 47.22% (17/36) and 61.67% (22/36), and there were statistical differences ( P<0.05); there were no statistical difference in ICU stay time, vasoactive drug use time and incidence of complication among control group, Dex1 group and Dex3 group ( P>0.05). Conclusions:Dex 0.20 to 0.40 μg/(kg·h) is well tolerated, and has less adverse reactions. It can effectively increase HRV, regulate the balance of sympathetic-vagal nerve tension, stabilize cardiovascular response and improve prognosis in patients with NSTEMI.