Dewey Frederick E, Freeman James V, Engel Gregory, Oviedo Raul, Abrol Nayana, Ahmed Natasha, Myers Jonathan, Froelicher Victor F
Stanford University School of Medicine, Stanford, CA, USA.
Am Heart J. 2007 Feb;153(2):281-8. doi: 10.1016/j.ahj.2006.11.001.
Although the prognostic power of heart rate variability (HRV) at rest has been demonstrated, the prognostic potential of exercise-induced HRV has not been investigated. We aimed to evaluate the prognostic power of exercise-induced HRV during and after standard exercise testing.
Time- and frequency-domain HRV analysis was performed on R-R interval data taken from 1335 subjects (95% male, mean age 58 years) during the first and last 2 minutes of exercise treadmill testing and the first 2 minutes of recovery. Cox survival analysis was performed for the 53 cardiovascular and 133 all-cause mortality end points that accrued during the 5.0-year mean follow-up.
After adjusting for potential confounders, greater root mean square successive difference in R-R interval during peak exercise and recovery, greater high-frequency (HF) power and percentage of HF power, lower percentage of low-frequency power, and lower ratio of low frequency to HF during recovery were significantly associated with increased risks for all-cause and cardiovascular death. Of all time-domain variables considered, the log of the root mean square successive difference during recovery was the strongest predictor of cardiovascular mortality (adjusted hazard ratio 5.0, 95% CI 1.5-17.0 for the top quintile compared with the lowest quintile). Log HF power during recovery was the strongest predictor of cardiovascular mortality in the frequency domain (adjusted hazard ratio 5.9, 95% CI 1.3-25.8 for the top quintile compared with the lowest quintile).
Exercise-induced HRV variables during and after clinical exercise testing strongly predict both cardiovascular and all-cause mortality independent of clinical factors and exercise responses in our study population.
尽管静息心率变异性（HRV）的预后能力已得到证实，但运动诱发的HRV的预后潜力尚未得到研究。我们旨在评估标准运动试验期间及之后运动诱发的HRV的预后能力。
对1335名受试者（95%为男性，平均年龄58岁）在运动平板试验的第1分钟和最后2分钟以及恢复的前2分钟采集的R-R间期数据进行时域和频域HRV分析。对5.0年平均随访期间出现的53个心血管死亡终点和133个全因死亡终点进行Cox生存分析。
在调整潜在混杂因素后，运动峰值和恢复期间R-R间期的均方根连续差更大、高频（HF）功率和HF功率百分比更高、恢复期间低频功率百分比更低以及低频与HF的比值更低，均与全因和心血管死亡风险增加显著相关。在所有考虑的时域变量中，恢复期间均方根连续差的对数是心血管死亡率的最强预测因子（最高五分位数与最低五分位数相比，调整后的风险比为5.0，95%CI为1.5-17.0）。恢复期间的对数HF功率是频域中心血管死亡率的最强预测因子（最高五分位数与最低五分位数相比，调整后的风险比为5.9，95%CI为1.3-25.8）。
在我们的研究人群中，临床运动试验期间及之后运动诱发的HRV变量能独立于临床因素和运动反应，强烈预测心血管和全因死亡率。
