© 2008 European Society of Cardiology
Reduced in vivo skeletal muscle oxygen consumption in patients with chronic heart failure—A study using Near Infrared Spectrophotometry (NIRS)
a Department of Cardiovascular Medicine, Medical School, University of Birmingham Edgbaston, Birmingham, B15 2TT, UK
b School of Sport and Exercise Sciences, University of Birmingham Edgbaston, Birmingham, B15 2TT, UK
* Corresponding author. Tel.: +44 121 414 5916; fax: +44 121 414 3713. E-mail address: abozguia{at}gmail.com (K. Abozguia).
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Abstract |
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Aim: We used Near Infrared Spectrophotometry (NIRS) during arterial occlusion to measure resting skeletal muscle oxygen consumption in chronic heart failure (CHF) patients and in age-matched healthy volunteers (HVs).
Methods: Fifteen CHF patients (ten males) and eleven HVs (six males) had echocardiographic evaluation followed by measurement of the oxygen consumption of the brachioradialis muscle using NIRS. This involved continuous measurement of the oxygenated haemoglobin concentration ([Oxy-Hb]) and deoxy-haemoglobin concentration ([Deoxy-Hb]) with an Oxiplex TS NIRS probe first under basal overnight fasted resting conditions followed by 1 min of forearm arterial occlusion. A linear decline was observed in [Oxy-Hb–Deoxy-Hb] during the arterial occlusion and the oxygen consumption rate was calculated from the initial slope observed.
Results: CHF patients were 59±2.8 years old with Left Ventricular Ejection Fraction (LVEF) 31%±2.2 and the HVs were 52±4.8 years old with LVEF 62%±2.5. The resting muscle oxygen consumption rate was significantly reduced in CHF patients versus HVs (0.04±0.01 mlO2/min/100 g versus 0.07±0.01 mlO2/min/100 g) p<0.005.
Conclusions: There is a significant reduction in resting oxygen consumption per gram of tissue in skeletal muscle of patients with CHF.
Key Words: Chronic heart failure • Skeletal muscle • Oxygen consumption • NIRS
Received December 22, 2007; Revised April 25, 2008; Accepted May 19, 2008