Athanasios Tasoulis

The addition of strength training to aerobic interval training: effects on muscle strength and body composition in CHF patients.

PURPOSE: The loss of lean muscle mass and muscle strength is a common problem in chronic heart failure (CHF) patients. Endurance training is efficient in improving patient exercise capacity. This study sought to evaluate the additional effects of strength training on muscle strength and body composition in chf patients participating in an interval training program. METHODS: Twenty consecutive, stable CHF patients participated in a rehabilitation program. Subjects were randomly assigned to aerobic (n = 10) or combined aerobic plus strength training group (n = 10). Aerobic group performed interval training on cycle ergometers. Strength training incorporated exercises for various muscle groups, including quadriceps, hamstrings, biceps brachii, and the deltoids. Both regimes were of the same duration. Body composition was evaluated by whole-body dual energy x-ray absorptiometry and quadriceps strength by the sum of the 2-repitition maximum (2-RM) test for each leg. Peak oxygen uptake ( ) and peak work load (Wpeak) as well as oxygen uptake ( ) and workload at anaerobic threshold (WAT) were evaluated by a symptom limited cardiopulmonary exercise testing. RESULTS: Concerning leg lean mass, no significant within-subjects or between-groups changes were observed (P > .05). Both groups improved in 2-RM test (P < .05), while a significant difference was observed between groups (P < .05). and and Wpeak and WAT were equally improved between training groups (P < .05). CONCLUSIONS: Combined aerobic interval and strength training induces a greater benefit than interval training alone on muscle strength in CHF patients. Adaptations other than hypertrophy, such as muscle fiber type alterations and/or neuromuscular adjustments, may account for these results.

Physical exercise improves the peripheral microcirculation of patients with chronic heart failure.

PURPOSE Patients with chronic heart failure (CHF) present with microcirculation alterations, partially attributed to endothelial dysfunction. Exercise training has been shown to induce beneficial effects in CHF patients. The aim of our study was to assess the effect of physical exercise on the microcirculation of CHF patients by near-infrared spectroscopy (NIRS). METHODS Sixteen consecutive stable CHF patients (men, n = 10; mean age = 50 ± 12 years) participated in a 3-month rehabilitation program (3 sessions per week). All patients performed symptom-limited, ramp-incremental cardiopulmonary exercise testing on a cycle ergometer before and after the completion of the program. Measurements included peak oxygen uptake (VO2peak), VO2 at anaerobic threshold (AT), and first-degree slope of VO2 during the first minute of recovery (VO2/t slope). Tissue oxygen saturation was continuously measured by NIRS at the thenar muscle during a 3-minute vascular occlusion with a pneumatic cuff (occlusion technique) before and after the rehabilitation program. RESULTS The oxygen reperfusion rate (%/min) following the release of vascular occlusion increased significantly after the rehabilitation program (450 ± 105 to 532 ± 151, P = .004) as did vascular reactivity (from 27 ± 13%/min to 39 ± 21%/min, P = .006). In addition, there was a significant increase in VO2peak and AT (from 14.3 ± 4.7 mL · kg−1 · min−1 to 16.7 ± 6.3 mL · kg−1 · min−1 and from 9.5 ± 3.6 mL · kg−1 · min−1 to 11.3 ± 4 mL · kg−1 · min−1, P = .007 and P = .012, respectively) as well as in VO2/t slope (from 0.35 ± 0.17 to 0.51 ± 0.07 mL · kg−1 · min−1, P = .005). CONCLUSIONS Peripheral microcirculation of CHF patients measured by NIRS improved after the rehabilitation program. NIRS is a noninvasive technique that could be used to evaluate the effect of rehabilitation on the peripheral microcirculation of CHF patients.

Skeletal muscle microcirculatory abnormalities are associated with exercise intolerance, ventilatory inefficiency, and impaired autonomic control in heart failure

BACKGROUND Several skeletal muscle abnormalities have been identified in patients with chronic heart failure (CHF), including endothelial dysfunction. We hypothesized that skeletal muscle microcirculation, assessed by near-infrared spectroscopy (NIRS), is impaired in CHF patients and is associated with disease severity. METHODS Eighty-three stable patients with mild-moderate CHF (72 males, mean age 54 ± 14 years, body mass index 26.7 ± 3.4 kg/m(2)) and 8 healthy subjects, matched for age, gender and body mass index, underwent NIRS with the vascular occlusion technique and cardiopulmonary exercise testing (CPET) evaluation on the same day. Tissue oxygen saturation (StO(2), %), defined as the percentage of hemoglobin saturation in the microvasculature compartments, was measured in the thenar muscle by NIRS before, during and after 3-minute occlusion of the brachial artery. Measurements included StO(2), oxygen consumption rate (OCR, %/min) and reperfusion rate (RR, %/min). All subjects underwent a symptom-limited CPET on a cycle ergometer. Measurements included VO(2) at peak exercise (VO(2)peak, ml/kg/min) and anaerobic threshold (VO(2)AT, ml/kg/min), VE/VCO(2) slope, chronotropic reserve (CR, %) and heart rate recovery (HRR(1), bpm). RESULTS CHF patients had significantly lower StO(2) (75 ± 8.2 vs 80.3 ± 6, p < 0.05), lower OCR (32.3 ± 10.4 vs 37.7 ± 5.5, p < 0.05) and lower RR (10 ± 2.8 vs 15.7 ± 6.3, p < 0.05) compared with healthy controls. CHF patients with RR ≥9.5 had a significantly greater VO(2)peak (p < 0.001), VO(2)AT (p < 0.01), CR (p = 0.01) and HRR(1) (p = 0.01), and lower VE/VCO(2) slope (p = 0.001), compared to those with RR <9.5. In a multivariate analysis, RR was identified as an independent predictor of VO(2)peak, VE/VCO(2) slope and HRR(1). CONCLUSIONS Peripheral muscle microcirculation, as assessed by NIRS, is significantly impaired in CHF patients and is associated with disease severity.

Peripheral Muscle Microcirculatory Alterations in Patients With Pulmonary Arterial Hypertension: A Pilot Study

BACKGROUND: Pulmonary microcirculation abnormalities are the main determinants of pulmonary arterial hypertension (PAH) pathophysiology. We hypothesized that PAH patients have peripheral tissue microcirculation alterations that might benefit from hyperoxic breathing. We evaluated peripheral muscle microcirculation with near-infrared spectroscopy, before and after hyperoxic breathing. METHODS: Eight PAH subjects, 8 healthy subjects (controls) matched for age, sex, and body mass index, and 16 subjects with chronic heart failure and matched for functional capacity with the PAH subjects underwent near-infrared spectroscopy. Tissue O2 saturation, defined as the hemoglobin saturation (%) in the microvasculature compartments, was measured on the thenar muscle. Then the 3-min brachial artery occlusion technique was applied before, during, and after 15 min of breathing 100% O2. We calculated the oxygen consumption rate (%/min), the reactive hyperemia time, and the time needed for tissue O2 saturation to reach its baseline value after the release of the occlusion. RESULTS: Compared to the controls, the PAH subjects had a significantly lower resting tissue O2 saturation (65.8 ± 14.9% vs 82.1 ± 4.0%, P = .005), a trend toward a lower oxygen consumption rate (35.3 ± 9.1%/min vs 43.4 ± 19.7%/min, P = .60), and a significantly higher reactive hyperemia time (3.0 ± 0.6 min vs 2.0 ± 0.3 min, P < .001). The PAH subjects also had lower tissue O2 saturation (P = .08), lower peripheral arterial oxygen saturation (P = .01), and higher reactive hyperemia time (P = .02) than the chronic heart failure subjects. After hyperoxic breathing, the PAH subjects had increased tissue O2 saturation (65.8 ± 14.9% to 71.4 ± 14.5%, P = .01), decreased oxygen consumption rate (35.3 ± 9.1%/min to 25.1 ± 6.6%/min, P = .01), and further increased reactive hyperemia time (3.0 ± 0.6 min to 4.2 ± 0.7 min, P = .007). CONCLUSIONS: The PAH subjects had substantial impairments of peripheral muscle microcirculation, decreased tissue O2 saturation (possibly due to hypoxemia), slower reactive hyperemia time, (possibly due to endothelium dysfunction), and peripheral systemic vasoconstriction. Acute hyperoxic breathing improved resting tissue O2 saturation (an expression of higher oxygen delivery) and decreased the oxygen consumption rate and reactive hyperemia time during reperfusion, possibly due to increased oxidative stress and evoked vasoconstriction.

Heart Rate Recovery and Oxygen Kinetics After Exercise in Obstructive Sleep Apnea Syndrome

Patients who suffer from obstructive sleep apnea (OSA) have a decreased exercise capacity and abnormal autonomic nervous function. However, the kinetics of early oxygen (O2) and heart rate recovery (HRR) have not been described.

The effort-reward imbalance questionnaire in Greek: translation, validation and psychometric properties in health professionals.

The Effort‐reward Imbalance Questionnaire in Greek: Translation, Validation and Psychometric Properties in Health Professionals: Pavlos MSAOUEL, et al. Greek Junior Doctors and Health Scientists Society, Greece—

Effects of interval exercise training on respiratory drive in patients with chronic heart failure

BACKGROUND Patients with chronic heart failure (CHF) suffer from ventilatory abnormalities. This study examined the effects of interval exercise training on the respiratory drive in CHF patients. METHODS Forty-six clinically stable CHF patients (38 males/8 women, mean age = 53 +/- 11 years) participated in an exercise rehabilitation program (ERP) 3 times/week, for 12 weeks by interval training modality with or without the addition of resistance training. All patients underwent symptom-limited cardiopulmonary exercise testing (CPET), and measurements of mouth occlusion pressure at 100 ms (P(0.1)) and maximum inspiratory muscle strength (P(Imax)) before and after ERP. Respiratory drive was estimated by mouth occlusion pressure P(0.1) and P(0.1)/P(Imax) ratio at rest, and the ventilatory pattern by resting mean inspiratory flow (V(T)/T(I)) and by V(T)/T(I) at identical CPET workloads, before and after ERP. We also studied a control non exercising group of 11 patients (8 men and 3 women). RESULTS P(0.1) at rest decreased from 3.04 +/- 1.52 to 2.62 +/- 0.9 cmH(2)O (p = 0.015), P(0.1)/P(Imax) % at rest from 4.56 +/- 3.73 to 3.69 +/- 2.03 (p = 0.006), resting V(T)/T(I) from 0.44 +/- 0.10 to 0.41 +/- 0.10 l/s (p = 0.014), and V(T)/T(I) at identical work rate from 2.13 +/- 0.59 to 1.93 +/- 0.58 l/s (p = 0.001) after ERP. VO(2) at peak exercise increased from 16.3 +/- 4.8 to 18.5 +/- 5.3 ml/kg/min (p < 0.001) in the exercise group. No improvement was noted in the control group. CONCLUSIONS ERP by interval training improves the respiratory drive and ventilatory pattern at rest and during exercise in CHF patients.

Beneficial effects of combined exercise training on early recovery cardiopulmonary exercise testing indices in patients with chronic heart failure.

PURPOSE: Exercise training induces several beneficial effects in patients with chronic heart failure (CHF). This study investigated the effects of high-intensity aerobic interval training (AIT) compared with combined AIT and strength training (COM) on early ventilatory and metabolic recovery pattern after symptom-limited cardiopulmonary exercise testing (CPET) in CHF patients. METHODS: Stable CHF patients (N = 42; 54 ± 10 years [mean ± SD], 35 males) participated in an exercise training program for 12 weeks, 3 times per week. Participants were randomly assigned to either AIT (n = 20) or COM group (n = 22). Cardiopulmonary exercise testing was performed before and after completion of the program. Primary measurements included absolute and percentage difference of oxygen uptake, carbon dioxide output, minute ventilation ( E), tidal volume (VT), respiratory rate, and the first-degree slope of oxygen uptake ( O2/t slope) and carbon dioxide output ( CO2/t slope) during the first minute of recovery after maximal exercise. RESULTS: The COM group had a greater improvement in the absolute and the percentage difference of E (P = .03 and P = .04, respectively) and respiratory rate (P = .02 and P = .01, respectively) during the first minute of recovery period after exercise compared with the AIT group alone. No significant changes were noted for VT measurements. A significant increase in CO2/t slope was observed in COM compared with the AIT group (P = .01). There was a trend for a greater increase in O2/t slope in the COM group (P = .07). CONCLUSIONS: The addition of strength training to AIT induces significant beneficial effects in terms of ventilatory and metabolic recovery kinetics than AIT alone in CHF patients, possibly indicating greater ventilatory efficiency and metabolic improvement.

Cardiopulmonary Rehabilitation Enhances Heart Rate Recovery in Patients With COPD

BACKGROUND: Autonomic dysfunction is present early in the course of COPD, and is associated with adverse outcomes. We utilized heart rate recovery, a simple and validated index of autonomic balance, to investigate the effects of exercise training on autonomic dysfunction in patients with COPD. METHODS: We evaluated 45 stable subjects with COPD who participated in a 36-session exercise-based cardiopulmonary rehabilitation program. Subjects underwent maximal cardiopulmonary exercise testing at baseline and after completion of the rehabilitation program. We recorded exercise testing parameters and heart rate during rest, exercise, and recovery. Heart rate recovery was calculated as heart rate at peak exercise minus heart rate at the first minute of recovery. RESULTS: Thirty-nine subjects (age 66.3 ± 7.8 y, 90% male, body mass index 27.1 ± 4.1 kg/m2, FEV1 45.7 ± 18.7%) completed the program. In these subjects, heart rate recovery increased from 16.2 ± 8.0 beats/min to 18.4 ± 8.4 beats/min (P = .01), resting heart rate decreased from 88.0 ± 10.7 beats/min to 83.3 ± 10.5 beats/min (P = .004), and heart rate at anaerobic threshold decreased from 109.0 ± 12.5 beats/min to 105.5 ± 11.7 beats/min (P = .040). In addition, oxygen consumption (V̇O2) increased from 14.3 ± 3.7 mL/kg/min to 15.2 ± 3.8 mL/kg/min at peak exercise, and from 9.7 ± 2.4 mL/kg/min to 10.4 ± 2.6 mL/kg/min at anaerobic threshold (both P = .02), while the V̇O2/t slope increased from –0.32 ± 0.16 mL/kg/min2 to –0.38 ± 0.19 mL/kg/min2 (P = .003). Parameters of ventilatory performance improved also. CONCLUSIONS: In subjects with COPD, exercise-based rehabilitation improves heart rate recovery, modestly though, which indicates a degree of attenuated autonomic dysfunction. Exercise and muscular oxidative capacity, as expressed by V̇O2/t slope, is also improved.

New insights into the exercise intolerance of β‐thalassemia major patients

The purpose of our study was assessment of the relative contribution of the systems involved in blood gas exchange to the limited exercise capacity in patients with β‐thalassemia major (TM) using integrative cardiopulmonary exercise testing (CPET) with estimation of oxygen kinetics. The study consisted of 15 consecutive TM patients and 15 matched controls who performed spirometric evaluation, measurement of maximum inspiratory pressure (Pimax) and an incremental symptom‐limited CPET on a cycle ergometer. Exercise capacity was markedly reduced in TM patients as assessed by peak oxygen uptake (pVO2, mL/kg/min: 22.1±6.6 vs 33.8±8.3; P<0.001) and anaerobic threshold (mL/kg/min: 13.0±3.0 vs 18.7±4.6; P<0.001) compared with controls. No ventilatory limitation to exercise was noted in TM patients (VE/VCO2 slope: 23.4±3.2 vs 27.8±2.6; P<0.001 and breathing reserve, %: 42.9±17.0 vs 29.5±12.0; P<0.005) and no difference in oxygen cost of work (peak VO2/WR, mL/min W: 12.2±1.7 vs 12.2±1.5; P=NS). Delayed recovery oxygen kinetics after exercise was observed in TM patients (VO2/t slope, mL/kg/min2: 0.67±0.27 vs 0.93±0.23; P<0.05) that was significantly correlated with Pimax at rest (r: 0.81; P<0.001). The latter was also significantly correlated to pVO2 (r: 0.84; P<0.001) and inversely correlated to ferritin levels (r: −0.6; P<0.02). Exercise capacity is markedly reduced in TM patients and this reduction is highly associated with the limited functional status of peripheral muscles.