白昼型特发性室性期前收缩的自主神经机制研究

目的 对白昼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的自主神经机制。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,将白昼(8:00~20:00)每小时室性期前收缩频度显著大于夜间(20:00~8:00)每小时室性期前收缩频度者定义为白昼型室性期前收缩。分析白昼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21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正相关。共分析典型室性期前收缩事件19阵,在室性期前收缩事件发生前存在心率的逐渐增加和迷走神经活性的逐渐下降。结论 部分特发性室性期前收缩在白昼时发作频度显著增加,室性期前收缩的发作频度与心率呈正相关,在室性期前收缩发生前,存在显著的心率加快和迷走神经活性的降低。该类室性期前收缩的发生可能与交感神经激活和(或)迷走神经张力下降有关。

Autonomic Mechanisms of Daytime Concentrated Idiopathic Premature Ventricular Contractions

Objective To investigate the autonomic mechanisms of idiopathic premature ventricular contractions (PVCs) through autonomic analysis of daytime type idiopathic PVCs. Methods 24-hour Holter ECG was monitored on idiopathic PVC patients and hourly densities of PVCs were calculated. PVCs with their daytime (8:00-20:00) hourly densities significantly higher than nighttime (20:00-8:00) hourly densities were defined as daytime concentrated PVCs. The relationship between hourly density and heart rate and heart rate variability changes in 30 minutes before typical PVC episodes were analyzed. Results Twenty-one cases of daytime type idiopathic PVCs were included and significant positive correlations between hourly PVC density and heart rate were found in all patients. Nineteen clusters of typical PVC episodes were analyzed. Gradual increase in heart rate and decrease in parasympathetic activity were found before PVC episodes. Conclusion Some idiopathic PVCs have significant higher frequencies during daytime with their frequencies positively related to heart rate. Before the occurrence of these PVCs, there are significant heart rate acceleration and decrease in parasympathetic activity. Sympathetic activation and (or) decrease in vagal tone may be involved in the occurrence of this type of PVCs.