急性冠脉综合征心率震荡昼夜节律及其与心率变异的相关性分析

目的 研究急性冠脉综合征患者心率震荡(heart rate turbulence,HRT)的昼夜节律性,并通过HRT指标与心率变异性指标的相关性分析,进一步探讨HRT与自主神经的关系.方法 连续入选急性冠脉综合征患者91例,分析一天中的两个时段即白天(7: 00～19: 00)和夜间(0: 00～6: 00)HRT的变化.从上午7: 00和凌晨0: 00开始各按顺序入选3个室早,根据文献计算HRT指标[震荡初始(TO)、震荡斜率(TS)]的数值.心率变异性选用的时域指标有SDNN、RMSSD,频域指标包括LF、HF、LF/HF.结果 ①TO值白天较夜间高,TS值白天较夜间低,均存在明显的昼夜节律.②TS与SDNN之间存在正相关关系(r=0.44),TS与LF/HF之间亦存在正相关关系(r=0.51).结论 急性冠脉综合征HRT存在昼夜节律变化且与HRV密切相关,提示HRT不仅反映心血管系统自主神经的反射性调节,在某种程度上也反映交感-迷走神经的紧张性调节.

Correlation between circadian rhythm of heart rate turbulence and heart rate variability in the patients with acute coronary syndrome

Objective To investigate the circadian rhythm of heart rate turbulence(HRT) in the patients with acute coronary syndrome and to discuss the relationship between HRT and autonomic nervous system by analyzing the correlation with heart rate variability(HRV). Methods 91 consecutive patients of acute coronary syndrome had sinus rhythm and at least ten ventricular premature complexes were found by 24-hour ambulatory electrocardiographic Holter monitoring. HRT parameters:turbulence onset(TO) and turbulence slope(TS)were calculated in two periods including day hours (7 a.m.～7 p.m.) and night hours ( 0 a.m.～6 a.m.).HRV time domain parameters SDNN and rMSSD were computed. Frequency-domain HRV parameters included LF, HF and LF/HF ratio. The correlations between the HRT and HRV higher in day hours than in night hours;The value of TS was significantly lower in day hours than in night hours;The two parameters of HRT correlations between TS and SDNN (r=0.44),LF/HF (r=0.51) in the patients with acute coronary syndrome (P＜0.05). Conclusion TS and TO have significant circadian rhythm between day time and night time in the patients with acute coronary syndrome. There were significant correlations between TS and some of HRV parameters,which indicates that HRT should be considered to reflect both baroreflex sensitivity and baseline tone of sympathetic and vagal modulation of the cardiovascular system.