Speeding of pulmonary VO₂ on-kinetics by light-to-moderate-intensity aerobic exercise training in chronic heart failure: Clinical and pathophysiological correlates

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• 作者：Aless ; ro Mezzani ; Bruno Grassi ; Andrew M. Jones ; Andrea Giordano ; Ugo Corr¨¤ ; Simone Porcelli ; Silvia Della Bella ; Adriano Taddeo ; Pantaleo Giannuzzi
• 关键词：Chronic heart failure ; Exercise training ; VO2 on-kinetics ; Peak oxygen consumption ; Near infrared spectroscopy ; Endothelial progenitor cells
• 刊名：International Journal of Cardiology
• 出版年：2013
• 出版时间：1 September, 2013
• 年：2013
• 卷：167
• 期：5
• 页码：2189-2195
• 全文大小：404 K

文摘

Background

Pulmonary VO₂ on-kinetics during light-to-moderate-intensity constant-work-rate exercise, an experimental model mirroring energetic transitions during daily activities, has been shown to speed up with aerobic exercise training (AET) in normal subjects, but scant data are available in chronic heart failure (CHF).

Methods and results

Thirty CHF patients were randomized to 3 months of light-to-moderate-intensity AET (CHF-AET) or control (CHF-C). Baseline and end-protocol evaluations included i) one incremental cardiopulmonary exercise test with near infrared spectroscopy analysis of peak deoxygenated hemoglobin + myoglobin concentration changes (¦¤[deoxy(Hb + Mb)]) in vastus lateralis muscle, ii) 8 light-to-moderate-intensity constant-work-rate exercise tests for VO₂ on-kinetics phase I duration, phase II ¦Ó, and mean response time (MRT) assessment, and iii) circulating endothelial progenitor cell (EPC) measurement. Reference values were obtained in 7 age-matched normals (N).

At end-protocol, phase I duration, phase II ¦Ó, and MRT were significantly reduced (? 12 % , ? 22 % , and ? 19 % , respectively) and peak VO₂, peak ¦¤[deoxy(Hb + Mb)], and EPCs increased (9 % , 20 % , and 98 % , respectively) in CHF-AET, but not in CHF-C. Peak ¦¤[deoxy(Hb + Mb)] and EPCs relative increase correlated significantly to that of peak VO₂ (r = 0.61 and 0.64, respectively, p < 0.05).

Conclusions

Light-to-moderate-intensity AET determined a near-normalization of pulmonary VO₂ on-kinetics in CHF patients. Such a marked plasticity has important implications for AET intensity prescription, especially in patients more functionally limited and with high exercise-related risk. The AET-induced simultaneous improvement of phase I and phase II, associated with an increase of peak peripheral oxygen extraction and EPCs, supports microcirculatory O₂ delivery impairment as a key factor determining exercise intolerance in CHF.