Effects of dexmedetomidine on cardiac electrophysiology in patients undergoing general anesthesia during perioperative period: a randomized controlled trial

BACKGROUND: Dexmedetomidine has controversial influence on cardiac electrophysiology. The aim of this study was to explore the effects of dexmedetomidine on perioperative cardiac electrophysiology in patients undergoing general anesthesia. METHODS: Eighty-one patients were randomly divided into four groups: groups D(1), D(2), D(3) receiving dexmedetomidine 1, 1, 0.5 μg/kg over 10 min and 1, 0.5, 0.5 μg/kg/h continuous infusion respectively, and control group (group C) receiving normal saline. Twelve-lead electrocardiograms were recorded at the time before dexmedetomidine/normal saline infusion (T(1)), loading dose finish (T(2)), surgery ending (T(6)), 1 h (T(7)) after entering PACU, 24 h (T(8)), 48 h (T(9)), 72 h (T(10)) and 1 month (T(11)) postoperatively. Cardiac circulation efficiency (CCE) were also recorded. RESULTS: Compared with group C, QTc were significantly increased at T(2) in groups D(1) and D(2) while decreased at T(7) and T(8) in group D(3) (P < 0.05), iCEB were decreased at T(8) (P < 0.05). Compared with group D(1), QTc at T(2), T(6), T(7), T(9) and T(10) and iCEB at T(8) were decreased, and CCE at T(2)-T(4) were increased in group D(3) significantly (P < 0.05). Compared with group D(2), QTc at T(2) and iCEB at T(8) were decreased and CCE at T(2) and T(3) were increased in group D(3) significantly (P < 0.05). CONCLUSIONS: Dexmedetomidine at a loading dose of 0.5 μg/kg and a maintenance dose of 0.5 μg/kg/h can maintain stability of cardiac electrophysiology during perioperative period and has no significant adverse effects on CCE. TRIAL REGISTRATION: ClinicalTrials.gov NCT04577430 (Date of registration: 06/10/2020).