Please see Bibliography of References for a list of abstracts, manuscripts and posters.
Kravari M, Anastasiou-Nana M, Gerovasili V, Drakos S, Dimopoulos S, Roditis P, Kardara E, Karatzanos L, Paliaki M, Nanas S. Am J Respir Crit Care Med. 2008;177(Abstracts Issue):A998.
Introduction: CHF patients develop abnormalities in peripheral muscle; physical training can benefit them. We evaluated the effect of a rehabilitation program on peripheral muscle oxygenation as assessed by NIRS.
Methods: 15 CHF patients participated in a rehabilitation program (36 sessions, 3times/wk) and performed symptom-limited cardiopulmonary exercise testing (CPET). We measured peak O2 uptake (VO2peak), O2 uptake at anaerobic threshold (AT) and during the first minute of recovery (VO2/t slope), ventilatory equivalent for CO2 (VE/VCO2), peak work rate (WRpeak). Muscle oxygen saturation (StO2) of quadriceps femoralis was measured continuously during exercise and recovery by NIRS. StO2 decrease rate during exercise and increase rate during recovery (StO2%/min) were calculated by linear regression. StO2 recovery data were curve-fit to a mono-exponential mathematical model: StO2(t)=StO2(b)+A1(1-e-(t-TD1)T1). The time constant (T1) was calculated before and after the program. p<0.05 indicated statistical significance.
Results: Exercise caused a significant increase in VO2peak and AT(15.5±4.7 vs.18±5.7 and 10.4±3.5 vs.11.8±3.7 ml/kg/min, respectively), as well as in WR peak (99.1±29 to 111±38 W) and VO2/tslope(0.42±0.2 vs. 0.58±0.3 ml/kg/min2). The StO2 increase rate during recovery was significantly higher (22.24±15 vs. 28±15 %/min), T1 was significantly lower (57.4±24.6 vs. 46.8±20.9 sec) after rehabilitation.
Conclusion: Exercise training improves exercise capacity and peripheral microcirculation function in CHF patients. NIRS can be used to assess muscle tissue O2 improvement after rehabilitation.