关键词: 心房颤动, 比索洛尔, 美托洛尔, 6 min步行试验, 心室率

Abstract: Objective　To evaluate the changes in ventricular rate in patients with atrial fibrillation（AF） treated by Bisoprolol versus Metoprolol during the 6-minute walk test（6MWT）.Methods　This retrospective study was conducted in 50 AF patients and 42 controls with normal sinus rhythm from September 2015 to September 2017.All of them underwent two rounds of 6MWT，first without taking drugs，then took drugs〔28 AF patients took Metoprolol（Metoprolol-treated AF subgroup） and 22 used Bisoprolol（Bisoprolol-treated AF subgroup），23 controls used Metoprolol（Metoprolol-treated control subgroup），and 19 took Bisoprolol（Bisoprolol-treated control subgroup）〕.The changes in ventricular rate in all the participants during the 6MWT under these two conditions were analyzed.And based on this，the impact of Metoprolol versus Bisoprolol on ventricular rate was compared.Results　During the 6MWT，the ventricular rate of all participants first increased but later decreased under the conditions of taking drugs or not.In general，the controls reached their maximal ventricular rate when the 6MWT was conducted for 5 minutes，while the AF patients reached their maximal ventricular rate when the 6MWT was conducted for 3 minutes，under the conditions of without taking drugs.The controls taking Metoprolol and those taking Bisoprolol attained their maximal ventricular rate when the 6MWT was conducted for 5，6 minutes，respectively.For AF patients using Metoprolol and those using Bisoprolol，the mean maximal ventricular rate was attained when the 6MWT was conducted for 3，5 minutes，respectively.5 minutes after the end of the 6MWT，the mean ventricular rates of controls taking Metoprolol and those taking Bisoprolol basically recovered to the baseline level without significant difference（P>0.05）.However，the mean ventricular rates of the AF patients using Metoprolol and those using Bisoprolol did not recover to the baseline level and showed significant difference（P<0.05）.Conclusion　Compared with Metoprolol，Bisoprolol produced a stronger impact on decreasing the maximal ventricular rate during the 6MWT，and it delayed the reappearance of the maximal ventricular rate，indicating that it may have greater potential for ventricular rate control.

Key words: Atrial fibrillation, Bisoprolol, Metoprolol, 6-minute walk test, Ventricular rate