运动试验对冠心病患者短程心率变异性的影响

目的探讨运动试验对冠心病患者短程心率变异性的影响。方法利用短程频域分析法检测12例冠心病(coronaryheartdisease,CHD)患者及年龄、性别相匹配的12例健康对照者(heaHhycontrolgroup,HCG)运动试验前、中、后不同阶段、体位的心率变异性(hearratevariability,HRV)。结果(1)CHD和HCG两组之间,运动前静卧位5minLFnorm、HFnorm、LF/HF均无显著差异(P>0.05)。CHD组运动前静卧位5min与运动后静卧位5min的频域各指标也无显著差异(P>0.05)。(2)CHD及HCG组LFnorm、HFnorm、LF/HF均表现为运动中逐渐降低,极量运动时达最低水平,恢复期逐渐升高的趋势(P<0.05)。两组组间运动终止后第2个5minLFnorm、HFnorm、LF/HF均无显著差异(P<0.05)。(3)CHD组与HCG组组间试验全程HRV频域分析中,CHD组的LF、HFnorm显著高于HCG组,CHD组的HF、HFnorm显著低于HCG组。结论(1)CHD患者静卧位无心肌缺血时交感迷走神经系统处于平衡状态。(2)运动诱导迷走神经兴奋性降低,恢复期逐渐恢复。(3)CHD患者运动恢复期HRV改变反映其缺血诱导的反射性的交感神经活性占优势。(4)运动状态下CHD患者存在自主神经系统失衡,说明运动试验有助于发现CHD患者的自主神经功能紊乱。

Effect of Exercise Testing on Short-term Heart Rate Variability in Patients with Coronary Heart Disease

Objective To study the effect of exercise testing on short term heart rate variability in patients with CHD.Methods In 12 patients with CHD and 12 age-and sex-matched healthy controls, short-term frequency domain analysis was performed at respective stage before, during and after ET.Results It showed that (1) No significant difference was detected in 5-minute frequency domain (LFnorm, HFnorm and LF/HF) of stationary supine position before exercise (P>0.05) between CHD and controls. In CHD, there was no significant difference in 5-minute frequency spectral components of supine position between pre-exercise and post-exercise results (P>0.05); (2) All of LFnorm, HFnorm and LF/HF were found to decrease gradually during ET and to reach the lowest levels in maximal ET and to increase during the recovery period in both CHD and controls (P<0.05).Between the two groups, significant difference was shown in the second 5-minute frequency domain analysis (LFnorm, HFnorm and LF/HF) after ET(P<0.05); (3) In the whole course of ET,the frequency domain analysis showed that LF and LFnorm were higher and HF,HFnorm were lower in CHD than those in controls.Conclusion It is concluded that (1) Sympathovagal nervous system remains balanced in patients with CHD in stationary supine position without myocardiac ischemia; (2) Vagal tone withdraws during the exercise time and increases during the recovery period; (3) The changes of HRV in patients with CHD present ischemia-induced reflective sympathetic activity predominance during the recovery period; (4) The autonomic nervous system in CHD is disordered during ET. This results suggest that ET is helpful in detecting the disorder of sympathovagal nervous system in patients with CHD.