Effects of different doses of dexmedetomidine on atrioventricular node conduction function in healthy volunteers / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effects of different doses of dexmedetomidine on atrioventricular node (AVN) conduction function in the healthy volunteers.Methods Sixteen healthy volunteers of both sexes,aged 18-30 yr,with body mass index of 19-26 kg/m2,were included in the study.Dexmedetomidine was infused in a loading dose of 1.0 μg/kg over 10 min,followed by an infusion of 0.5 μg · kg-1 · h 1 for 50 min (Dose Ⅰ);1-2 weeks later,dexmedetomidine was infused in a loading dose of 1.5 μg/kg over 10 min,followed by an infusion of 0.75 μg · kg-1 · h-1 for 50 min (Dose Ⅱ).Before infusion of dexmedetomidine (T0) and at 15 and 35 min of infusion (T1.2),AVN Wenckebach point,AVN 2 ∶ 1 block point,AVN relative refractory period (AVNRRP),and AVN effective refractory period (AVNERP) were measured.Results AVN Wenckebach point and AVN 2 ∶ 1 block point were significantly decreased,and AVNRRP and AVNERP were significantly prolonged at T1,2 compared with those at T0 (P＜0.05).Compared with Dose Ⅰ,AVN Wenckebach point at T2 and AVN 2 ∶ 1 block point at T1,2 were significantly decreased,and AVNRRP and AVNERP were significantly prolonged at T1,2 in the subjects receiving Dose Ⅱ] (P＜0.05).Conclusion Dexmedetomidine can inhibit AVN conduction function in the healthy volunteers,and the inhibitory effect is enhanced with the increasing doses.