Department of Physical Therapy, Virginia Commonwealth University, Health Sciences Campus, Richmond, Virginia 23298-0224, USA.
J Card Fail. 2009 Aug;15(6):482-8. doi: 10.1016/j.cardfail.2008.12.015. Epub 2009 Feb 10.
Ventilatory efficiency (VE/VCO(2) ratio) and the partial pressure of end-tidal carbon dioxide (P(ET)CO(2)), obtained during moderate to high levels of physical exertion demonstrate prognostic value in heart failure (HF). The present investigation assesses the clinical utility of these variables during low-intensity exercise.
One hundred and thirty subjects diagnosed with HF underwent a 2-minute, constant-rate treadmill session at 2 miles per hour. Both the VE/VCO(2) ratio and P(ET)CO(2) were recorded during exercise (30-second average) and their change (Delta) from rest. B-type and atrial natriuretic peptide (BNP and ANP) were also determined. Only P(ET)CO(2) and DeltaP(ET)CO(2) emerged from the multivariate Cox regression. Receiver operating characteristic curve analysis revealed the prognostic classification schemes were significant with thresholds of < or >or=34 mm Hg (hazard ratio: 4.2, 95% CI: 2.2-8.0, P < .001) and < or >or=1 mm Hg (hazard ratio: 3.5, 95% CI: 1.9-6.6, P < .001) being optimal for P(ET)CO(2) and DeltaP(ET)CO(2), respectively. Moreover, subjects with a P(ET)CO(2)>or=34 mm Hg had a significantly lower BNP (214.1 +/- 431.9 vs. 1110.5 +/- 1854.0 pg/mL, P=.005) and ANP (108.2 +/- 103.6 vs. 246.2 +/- 200.4 pg/mL, P < .001).
The results of this pilot study indicate ventilatory expired gas analysis during a short bout of low-intensity exercise may provide insight into prognosis and cardiac stability.
在中等至高强度的体力活动中，通气效率（VE/VCO2 比值）和呼气末二氧化碳分压（P（ET）CO2）可反映心力衰竭（HF）的预后价值。本研究评估了这些变量在低强度运动中的临床应用价值。
130 名 HF 患者进行了 2 分钟，2 英里/小时的恒定速率跑步机运动。在运动过程中（30 秒平均值）和休息时（Δ）记录 VE/VCO2 比值和 P（ET）CO2。还测定了 B 型和心房利钠肽（BNP 和 ANP）。仅 P（ET）CO2 和ΔP（ET）CO2 从多元 Cox 回归中得出。受试者工作特征曲线分析显示，预测分类方案具有显著性，阈值分别为 < 或 ≥ 34mmHg（危险比：4.2，95%CI：2.2-8.0，P <.001）和 < 或 ≥ 1mmHg（危险比：3.5，95%CI：1.9-6.6，P <.001），对 P（ET）CO2 和ΔP（ET）CO2 最为有利。此外，P（ET）CO2 ≥ 34mmHg 的患者 BNP 显著降低（214.1 ± 431.9 vs. 1110.5 ± 1854.0pg/ml，P =.005）和 ANP（108.2 ± 103.6 vs. 246.2 ± 200.4pg/ml，P <.001）。
本研究结果表明，在短时间的低强度运动中进行通气呼气气体分析可能有助于了解预后和心脏稳定性。
