Department of Rehabilitation, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University Health Science Centre, Shenzhen, China.
School of Health and Rehabilitation Sciences, The University of Queensland, Queensland, Australia.
PLoS One. 2022 Aug 30;17(8):e0273794. doi: 10.1371/journal.pone.0273794. eCollection 2022.
The 6-minute walk test (6MWT) is a field test commonly used to predict peak oxygen consumption (VO2peak) in people after stroke. Inclusion of cardiodynamic variables measured by impedance cardiography (ICG) during a 6MWT has been shown to improve prediction of VO2peak in healthy adults but these data have not been considered in people after stroke. This study investigates whether the prediction of VO2peak can be improved by the inclusion of cardiovascular indices derived by impedance cardiography (ICG) during the 6MWT in people after stroke.
This was a cross-sectional study. Patients diagnosed with stroke underwent in random order, a maximal cardiopulmonary exercise test (CPET) and 6MWT in separate dates. Heart rate (HR), stroke volume (SV) and cardiac output (CO) were measured by ICG during all tests. Oxygen consumption was recorded by a metabolic cart during the CPET. Recorded data were subjected to multiple regression analyses to generate VO2peak prediction equations.
Fifty-nine patients, mean age 50.0±11.7 years were included in the analysis. The mean distance covered in the 6MWT (6MWD) was 294±13 m, VO2peak was 19.2±3.2 ml/min/kg. Mean peak HR, SV and CO recorded during 6MWT were 109±6 bpm, 86.3±8.8 ml, 9.4±1.2 L/min and during CPET were 135±14 bpm, 86.6±9 ml, 11.7±2 L/min respectively. The prediction equation with inclusion of cardiodynamic variables: 16.855 + (-0.060 x age) + (0.196 x BMI) + (0.01 x 6MWD) + (-0.416 x SV6MWT) + (3.587 x CO 6MWT) has a higher squared multiple correlation (R2) and a lower standard error of estimate (SEE) and SEE% compared to the equation using 6MWD as the only predictor.
Inclusion of SV and CO measured during the 6MWT in stroke patients further improved the VO2peak prediction power compared to using 6MWD as a lone predictor.
6 分钟步行测试（6MWT）是一种常用于预测中风后患者峰值耗氧量（VO2peak）的现场测试。在 6MWT 期间测量阻抗心动图（ICG）的心脏动力学变量已被证明可以改善健康成年人的 VO2peak 预测，但这些数据尚未在中风后患者中考虑。本研究旨在探讨在中风后患者的 6MWT 期间纳入由阻抗心动图（ICG）得出的心血管指数是否可以提高 VO2peak 的预测能力。
这是一项横断面研究。患有中风的患者按随机顺序在不同日期分别进行最大心肺运动测试（CPET）和 6MWT。在所有测试中，通过 ICG 测量心率（HR）、每搏量（SV）和心输出量（CO）。在 CPET 期间，通过代谢箱记录耗氧量。记录的数据进行多元回归分析，生成 VO2peak 预测方程。
共有 59 名患者（平均年龄 50.0±11.7 岁）纳入分析。6MWT 中的平均步行距离（6MWD）为 294±13 m，VO2peak 为 19.2±3.2 ml/min/kg。在 6MWT 期间记录的平均峰值 HR、SV 和 CO 分别为 109±6 bpm、86.3±8.8 ml、9.4±1.2 L/min，在 CPET 期间记录的平均峰值 HR、SV 和 CO 分别为 135±14 bpm、86.6±9 ml、11.7±2 L/min。纳入心脏动力学变量的预测方程：16.855 + (-0.060 x 年龄) + (0.196 x BMI) + (0.01 x 6MWD) + (-0.416 x SV6MWT) + (3.587 x CO 6MWT)，与仅使用 6MWD 作为唯一预测因子的方程相比，具有更高的平方多重相关系数（R2）和更低的估计标准误差（SEE）和 SEE%。
与仅使用 6MWD 作为唯一预测因子相比，在中风患者的 6MWT 期间纳入 SV 和 CO 的测量值可进一步提高 VO2peak 的预测能力。
