Division of Cardiovascular Medicine, Department of Medicine, Stanford, California, USA; Division of Sports and Exercise Medicine, Department of Medicine, University of Padova, Padova, Italy.
Division of Cardiovascular Medicine, Department of Medicine, Stanford, California, USA; Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel.
Clinics (Sao Paulo). 2023 Jun 23;78:100225. doi: 10.1016/j.clinsp.2023.100225. eCollection 2023.
Cardiopulmonary Exercise Testing (CPX) is essential for the assessment of exercise capacity for patients with Chronic Heart Failure (CHF). Respiratory gas and hemodynamic parameters such as Ventilatory Efficiency (VE/VCO slope), peak oxygen uptake (peak VO), and heart rate recovery are established diagnostic and prognostic markers for clinical populations. Previous studies have suggested the clinical value of metrics related to respiratory gas collected during recovery from peak exercise, particularly recovery time to 50% (T1/2) of peak VO. The current study explores these metrics in detail during recovery from peak exercise in CHF.
Patients with CHF who were referred for CPX and healthy individuals without formal diagnoses were assessed for inclusion. All subjects performed CPX on cycle ergometers to volitional exhaustion and were monitored for at least five minutes of recovery. CPX data were analyzed for overshoot of respiratory exchange ratio (RER=VCO/VO), ventilatory equivalent for oxygen (VE/VO), end-tidal partial pressure of oxygen (PETO), and T1/2 of peak VO and VCO.
Thirty-two patients with CHF and 30 controls were included. Peak VO differed significantly between patients and controls (13.5 ± 3.8 vs. 32.5 ± 9.8 mL/Kg*min, p < 0.001). Mean Left Ventricular Ejection Fraction (LVEF) was 35.9 ± 9.8% for patients with CHF compared to 61.1 ± 8.2% in the control group. The T1/2 of VO, VCO and VE was significantly higher in patients (111.3 ± 51.0, 132.0 ± 38.8 and 155.6 ± 45.5s) than in controls (58.08 ± 13.2, 74.3 ± 21.1, 96.7 ± 36.8s; p < 0.001) while the overshoot of PETO, VE/VO and RER was significantly lower in patients (7.2 ± 3.3, 41.9 ± 29.1 and 25.0 ± 13.6%) than in controls (10.1 ± 4.6, 62.1 ± 17.7 and 38.7 ± 15.1%; all p < 0.01). Most of the recovery metrics were significantly correlated with peak VO in CHF patients, but not with LVEF.
Patients with CHF have a significantly blunted recovery from peak exercise. This is reflected in delays of VO, VCO, VE, PETO, RER and VE/VO, reflecting a greater energy required to return to baseline. Abnormal respiratory gas kinetics in CHF was negatively correlated with peak VO but not baseline LVEF.
心肺运动测试（CPX）对于评估慢性心力衰竭（CHF）患者的运动能力至关重要。通气效率（VE/VCO 斜率）、峰值摄氧量（peak VO）和心率恢复等呼吸气体和血流动力学参数是临床人群的既定诊断和预后标志物。先前的研究表明，在从峰值运动中恢复期间收集的与呼吸气体相关的指标具有临床价值，特别是峰值 VO 恢复到 50%（T1/2）的时间。本研究详细探讨了 CHF 患者在从峰值运动中恢复时的这些指标。
对因 CPX 而就诊的 CHF 患者和无正式诊断的健康个体进行评估，以确定是否符合纳入标准。所有受试者均在自行车测力计上进行至力竭的 CPX，并至少监测 5 分钟的恢复期。分析 CPX 数据以了解呼吸交换率（RER=VCO/VO）、氧通气当量（VE/VO）、呼气末氧分压（PETO）以及 peak VO 和 VCO 的 T1/2 。
共纳入 32 例 CHF 患者和 30 例对照者。患者的峰值 VO 明显低于对照组（13.5 ± 3.8 与 32.5 ± 9.8 mL/Kg*min，p<0.001）。CHF 患者的平均左心室射血分数（LVEF）为 35.9 ± 9.8%，而对照组为 61.1 ± 8.2%。与对照组相比，患者的 VO、VCO 和 VE 的 T1/2 明显更高（111.3 ± 51.0、132.0 ± 38.8 和 155.6 ± 45.5s）（p<0.001），而患者的 PETO、VE/VO 和 RER 的过冲明显更低（7.2 ± 3.3、41.9 ± 29.1 和 25.0 ± 13.6%）（p<0.01）。CHF 患者的大多数恢复期指标与 peak VO 显著相关，但与 LVEF 无关。
CHF 患者的峰值运动后恢复明显减弱。这反映在 VO、VCO、VE、PETO、RER 和 VE/VO 的延迟，这反映出需要更多的能量才能恢复到基线。CHF 中的异常呼吸气体动力学与 peak VO 呈负相关，而与基线 LVEF 无关。
