不同昼夜节律流出道室性早搏患者自主神经活性的变化

Changes of autonomic nervous system activity in patients with different circadian rhythm of outflow tract premature ventricular contractions

目的探讨不同昼、夜节律的流出道室性早搏（OT-PVC）自主神经活性的变化特点，为临床针对不同昼、夜节律表现的室性早搏（室早）选择适当的治疗策略提供线索。方法选择2014年11月至2015年11月在大连医科大学附属第一医院住院的OT-PVC患者53例行24h动态心电图检查，所有患者按照昼（8：00～20：00）夜（20：00-8：00）室早负荷不同分为A组（日间室早负荷为主型）、B组（夜间室早负荷为主型）及C组（昼、夜室早负荷均衡型）3个亚组，其中昼、夜室早负荷均衡定义为昼、夜室早负荷差值的绝对值≤10％室早总负荷。并与71例正常对照组比较临床资料、心率变异性（HRV）各参数及24h正常窦性RR间期总体标准差（SDNN）趋势的差异。结果室早组各HRV参数[SDNN、每5min节段窦性RR间期均值的标准差（SDANN）、相邻RR间期差值超过50ms的RR间期所占百分数（PNN50）、低频功率（LF）、高频功率（HF）]均明显高于正常对照组（P〈0．05）。各组24h各时段SDNN水平趋势图中，对照组SDNN在1d中基本趋于稳定．其值在4组间表现出最低水平：C组24h SDNN有大幅度波动，但总体在4组间呈现出较高水平；A组SDNN水平在24h中均明显高于正常对照组，与C组总体趋势保持一致，但不及C组波动幅度大；B组SDNN水平在日间段有小范围波动，总体趋势与正常对照组保持一致．但在夜间段明显高于正常对照组。结论日间室早负荷为主型的OT-PVC可能为交感神经介导，其自主神经活性无论昼、夜较常人均升高；夜间室早负荷为主型的OT-PVC可能为迷走神经介导，其自主神经活性在白天与正常人无异，但在夜间明显升高。

Objective To evaluate autonomic nervous activity in patients with different circadian rhythm of outflow tract premature ventricular contractions （OT-PVC）. Methods Fifty-three patients diagnosed as OT-PVC from November 2014 to November 2015 at the 1st Affiliated Hospital of Dalian Medical University had been recruited into the study, and were divided into group A [ premature ventricular contractions （PVC） load mainly in daytime ], group B （PVC load mainly in nighttime）and group C （balanced load during the day and night）based on their different PVC load during day（ 8：00 am to 8：00 pm）and night（ 8：00 pm to next day 8：00 am）.Balanced load was defined as less than 10%（ including 10% ）of the difference in the number of PVC between day and night. Seventy-one subjects without any known diseases served as control and their baseline data,HRV parameters and hourly tend of SDNN were compared among groups. Results Each HRV parameter（SDANN, SDNN, PNN50, LF, HF）in PVC groups was significantly higher than that in control group （ P〈0. 05 ）. From 24 hours SDNN trend chart, SDNN in control group tended to be stable during the day and night, and exhibited the lowest level among 4 groups. SDNN in group C had wide fluctuations, but overall showed higher levels than any other group during 24 hours.SDNN in group A was significantly higher than that in control group on the whole day,the overall trend was consistent with group C,but had less fluctuation.SDNN in group B had a small range of fluctuation in the daytime;the trend was close to control group,while the levels were significantly higher than control group during the night. Conclusion Group A （PVC load mainly in daytime） may be sympathetically mediated, their autonomic nervous system activity in both day and night was increased comparing with normal people.Group B（ PVC load mainly in nighttime）may be parasympathetic mediated, which was no difference in autonomic nervous system activity during the daytime, but will increase signifi- cantly at night comparing with normal people.