A practical approach to assess leg muscle oxygenation during ramp-incremental cycle ergometry in heart failure

Abstract

Heart failure is characterized by the inability of the cardiovascular system to maintain oxygen (O2) delivery (i.e., muscle blood flow in non-hypoxemic patients) to meet O2 demands. The resulting increase in fractional O2 extraction can be non-invasively tracked by deoxygenated hemoglobin concentration (deoxi-Hb) as measured by near-infrared spectroscopy (NIRS). We aimed to establish a simplified approach to extract deoxi-Hb-based indices of impaired muscle O2 delivery during rapidly-incrementing exercise in heart failure. We continuously probed the right vastus lateralis muscle with continuous-wave NIRS during a ramp-incremental cardiopulmonary exercise test in 10 patients (left ventricular ejection fraction <35%) and 10 age-matched healthy males. Deoxi-Hb is reported as % of total response (onset to peak exercise) in relation to work rate. Patients showed lower maximum exercise capacity and O2 uptake-work rate than controls (P<0.05). The deoxi-Hb response profile as a function of work rate was S-shaped in all subjects, i.e., it presented three distinct phases. Increased muscle deoxygenation in patients compared to controls was demonstrated by: i) a steeper mid-exercise deoxi-Hb-work rate slope (2.2±1.3 vs 1.0±0.3% peak/W, respectively; P<0.05), and ii) late-exercise increase in deoxi-Hb, which contrasted with stable or decreasing deoxi-Hb in all controls. Steeper deoxi-Hb-work rate slope was associated with lower peak work rate in patients (r=–0.73; P=0.01). This simplified approach to deoxi-Hb interpretation might prove useful in clinical settings to quantify impairments in O2 delivery by NIRS during ramp-incremental exercise in individual heart failure patients.

Non-invasively measured central and peripheral factors of oxygen uptake differ between patients with chronic heart failure and healthy controls

“…The maximum oxygen uptake of the patients was 15.6 ± 3.0 ml/kg/min, whereas healthy controls had 28.0 ± 2.1 ml/kg/min (− 44.3%). Previous studies support these findings: 15.4 ± 4.9 vs. 23.1 ± 3.0 ml/kg/min (− 33.3%) [18], 15.2 ± 1.1 vs. 21.1 ± 1.7 ml/kg/min (− 28.0%) [25], and 20.1 ± 6.0 vs. 33.3 ± 7.0 ml/kg/min (− 39.6%) [19]. This outcome reinforces the well-known negative impact of chronic heart failure on maximum oxygen uptake and performance capacity.…”

“…Inclusion criteria for both groups were an age of 50–70 years and less than 3 h of exercise per week, so that both groups matched based on their activity level. Additionally, due to the definition considering heart failure with reduced ejection fraction, patients were included when an ejection fraction of ≤35% was present, as investigated before [ 18 , 28 ]. This ensured that typical heterogeneity of chronic heart failure such as etiologies, demographics and co-morbidities was reduced [ 1 ].…”

“…Still, the aforementioned central and peripheral factors are often insufficiently addressed, because they are usually measured invasively [17]. Especially taken the importance of the cardiac power output and peripheral changes into account [9-11, 13, 14], it is promising to assess central and peripheral factors of oxygen uptake by recent noninvasive technologies such as bioreactance analysis and near-infrared spectroscopy [10,[17][18][19].…”

Evolution of Muscular Oxygenation during a Walking Test in Preterm Children

“…Cardiac and muscular pathologies, such as Becker Muscular Distrophy (BMD), also have a negative impact on O2 extraction, due to an insufficient blood delivery. O2 extraction is h m z ∆HHb h c r to compensate disorders in O2 delivery (18,31).…”

Physical Exercise in the Management of Erectile Dysfunction in Patients with Heart Failure

“…The presence of peripheral hypoperfusion in HF patients with impaired LVEF 3,5,48,52 contributes to aggravate ED, 4,10,11 worsening functional status and exercise tolerance. 5,[53][54][55] The symptoms of HF (dyspnea, fatigue, and exercise intolerance) are among the main factors responsible for impairing sexual function. 5,13 The results of this review demonstrated that physical exercise in different intensities was able to promote significant improvement in functional capacity and tolerance to exercise in patients with HF and ED when evaluated by cardiopulmonary test.…”