a Faculty of Medical Sciences, Cardiovascular Research Centre, Institutes of Cellular and Genetic Medicine , Newcastle University, and Newcastle upon Tyne Hospitals , Newcastle upon Tyne , UK.
b Department of Primary Care Health Sciences , University of Oxford , Oxford , UK.
Scand Cardiovasc J. 2019 Apr;53(2):77-82. doi: 10.1080/14017431.2019.1590629. Epub 2019 Apr 8.
Heart rate variability (HRV) and haemodynamic response to exercise (i.e. peak cardiac power output) are strong predictors of mortality in heart failure. The present study assessed the relationship between measures of HRV and peak cardiac power output.
In a prospective observational study of 33 patients (age 54 ± 16 years) with chronic heart failure with reduced left ventricular ejection fraction (29 ± 11%), measures of the HRV (i.e. R-R interval and standard deviation of normal R-R intervals, SDNN) were recorded in a supine position. All patients underwent maximal graded cardiopulmonary exercise testing with non-invasive (inert gas rebreathing) cardiac output assessment. Cardiac power output, expressed in watts, was calculated as the product of cardiac output and mean arterial blood pressure.
The mean RR and SDNN were 837 ± 166 and 96 ± 29 ms, peak exercise cardiac power output 2.28 ± 0.85 watts, cardiac output 10.34 ± 3.14 L/min, mean arterial blood pressure 98 ± 14 mmHg, stroke volume 91.43 ± 40.77 mL/beat, and oxygen consumption 19.0 ± 5.6 mL/kg/min. There was a significant but only moderate relationship between the RR interval and peak exercise cardiac power output (r = 0.43, p = .013), cardiac output (r = 0.35, p = .047), and mean arterial blood pressure (r = 0.45, p = .009). The SDNN correlated with peak cardiac power output (r = 0.42, p = .016), mean arterial blood arterial (r = 0.41, p = .019), and stroke volume (r = 0.35, p = .043).
Moderate strength of the relationship between measures of HRV and cardiac response to exercise suggests that cardiac autonomic function is not good indicator of overall function and pumping capability of the heart in chronic heart failure.
心率变异性（HRV）和运动时的血液动力学反应（即峰值心输出功率）是心力衰竭患者死亡率的强有力预测指标。本研究评估了 HRV 与峰值心输出功率之间的关系。
在一项对 33 名慢性心力衰竭伴有左心室射血分数降低（29±11%）的患者（年龄 54±16 岁）的前瞻性观察研究中，在仰卧位记录了 HRV 的各项指标（即 R-R 间期和正常 R-R 间期的标准差，SDNN）。所有患者均接受最大分级心肺运动测试，并进行无创（惰性气体再呼吸）心输出量评估。心输出量以瓦特表示，计算方法为心输出量乘以平均动脉血压。
平均 RR 间期和 SDNN 分别为 837±166ms 和 96±29ms，峰值运动心输出功率为 2.28±0.85 瓦特，心输出量为 10.34±3.14L/min，平均动脉血压为 98±14mmHg，每搏量为 91.43±40.77mL/beat，耗氧量为 19.0±5.6mL/kg/min。RR 间期与峰值运动心输出功率（r=0.43，p=0.013）、心输出量（r=0.35，p=0.047）和平均动脉血压（r=0.45，p=0.009）呈显著但仅中度相关。SDNN 与峰值心输出功率（r=0.42，p=0.016）、平均动脉血压（r=0.41，p=0.019）和每搏量（r=0.35，p=0.043）相关。
HRV 与运动时心脏反应之间的关系强度适中，表明心脏自主功能不能很好地反映心力衰竭患者心脏的整体功能和泵血能力。
