夜间型特发性室性期前收缩的自主神经机制研究

Autonomic Mechanisms of Nocturnal Idiopathic Premature Ventricular Contractions

目的对夜间发作增多的特发性室性期前收缩进行自主神经指标分析，探讨特发性室性期前收缩与心脏自主神经调控的关系。方法本研究对特发性室性期前收缩患者进行了长程心电图检查，计算每小时室性期前收缩频度，将夜间（20：00～8：00时）每小时室性期前收缩频度显著大于白昼（8：00～20：00时）每小时室性期前收缩频度者定义为夜间型室性期前收缩。分析夜间型室性期前收缩的频度与心率的相关性以及典型室性期前收缩事件发生前30min内的心率变异性指标变化。结果共纳入符合条件的室性期前收缩患者19例，每例患者的室性期前收缩频度与每小时平均心率均呈显著负相关。共分析典型室性期前收缩事件8阵，在室性期前收缩事件发生前短时间内存在心率的逐渐减慢，但心率变异性指标的变化差异无统计学意义（P〉0．05）。结论部分特发性室性期前收缩在夜间发作频度显著增加，室性期前收缩的发作频度与心率呈负相关，在室性期前收缩发生前，可观察到显著的心率减慢。该现象对室性期前收缩的治疗可能具有一定的指导意义。

Objective To investigate the autonomic mechanisms of idiopathic premature ventrieular contractions （PVCs） through autonomic analysis of nocturnal idiopathic PVCs. Methods 24 - hour Hoher ECG was monitored on idiopathic PVC patients and hourly densities of PVCs were calculated. PVCs with their nighttime （20：00 -8：00） hourly densities significantly higher than daytime （8：00 - 20：00） hourly densities were defined as nocturnal PVCs. The relationship between hourly density and heart rate and changes in heart rate variability in 30 minutes before typical PVC episodes were analyzed. Results 19 cases of nocturnal idiopathic PVCs were included and significant negative correlations between hourly PVC density and heart rate were found in all patients. 8 clusters of typical PVC episodes were analyzed. Gradual decreases in heart rate were found before PVC episodes while no evident change in heart rate variability was observed. Conclusion Some idiopathic PVCs have significant higher frequencies during nighttime with their frequencies negatively related to heart rate. Before the occurrence of these PVCs, there are significant heart rate decelerations. The phenomenon might be helpful in the treatment of idiopathic PVCs.