134 Exercise training does not improve oxygen uptake kinetics in chronic heart failure
MGK Gademan1; LJSM Teppema1; HF Verwey1; JCW Haest1; HJ Van Exel2; CMHB Lucas3; S Somer4; MJ Schalij2; EE Van Der Wall2; CA Swenne2
1Leiden University Medical Centre, Leiden, Netherlands
2Rijnland Rehabilitation Center, Leiden, Netherlands
3Rijnland Hospital, Leiderdorp, Netherlands
4Bronovo Hospital, Den Haag, Netherlands
Purpose: Several cardiopulmonary exercise-testing variables, like VO2 peak, VE/VCO2slope, oxygen uptake efficiency slope (OUES), and VO2 kinetics (the ratio of the increase in oxygen uptake to work rate increment, dVO2/dW) have predictive value in chronic heart failure (CHF). Exercise training is known to improve VO2 peak, VE/VCO2 slope, OUES and prognosis in CHF patients. Whether exercise training also improves dVO2/dW is currently unknown. We hypothesize that exercise training also improves dVO2/dW in CHF.
Methods: We studied 37 NYHA-class II-III CHF patients who constituted an exercise training group T (N=23; 19M/4F; age 60±10 yrs; LVEF 33±7%) and a control group C (N=14; 13M/1F; age 62±10 yrs; LVEF 36±4%). A symptom-limited exercise test was done at baseline and repeated after four weeks (C) or after completion of the training program (T).
Results: Exercise training increased VO2 peak by 19% (P(TvsC) >0.001), OUES by 17% (P(TvsC)>0.01), Wmax by 14%(P(TvsC) >0.01) and decreased VE/VCO2 slope by 9% (P(TvsC)>0.05). Exercise training did not increase dVO2/dW (9.79 UNITS before training versus 9.64 UNITS after training, P(TvsC)=0.83).
Conclusions: In contrast to VO2 peak, VE/VCO2 and OUES, the oxygen uptake kinetics dVO2/dW did not improve after exercise training. This finding prompts for further research, to reveal which code-terminants of dVO2/dW (cardiac output response to exercise, pulmonary and vascular components of oxygen delivery, components of oxygen utilization) cause this lack of training effect.
135 Impact of cardiac transplantation on the Oxygen Uptake Efficiency Slope (OUES) and correlation with peak VO2 and VE/VCO2 slope
RK Binder; R Hullin; T Carrel; H Saner; P Mohacsi; J-P Schmid
Inselspital, University Hospital Bern Cardiovascular Prevention & Rehabilitation, Bern, Switzerland
Background: The oxygen uptake efficiency slope (OUES), based on the relation of log transformed ventilation (VE) and oxygen uptake (VO2), has been shown to be highly reproducible and independent of exercise effort or duration. Patients before and after heart transplantation (HTx) are often unable to furnish a maximal effort. We therefore aimed to compare the change of the OUES post transplant with peak VO2 and VE/VCO2 slope, two established parameters of maximal exercise performance.
Methods: Sixteen HTx recipients (12 male, mean age 44.7±12.1 years, mean preoperative ejection fraction 20.6±4.6%) were included into the study. They underwent symptom limited cardio-pulmonary exercise testing on a cycle ergometer before (7±9 months) and after (34±17 months) HTx.
Results: OUES significantly improved from 1221±500 to 1650±589 (p=0.009) while VE/VCO2-slope significantly decreased from 41.7±9.9 to 35.5±4.9 (p=0.017). Peak oxygen consumption significantly improved from 15.4±4.3 to 21.4±6.6 ml/kg/min. (p=0.004). The OUES correlated highly significantly with peak VO2 (r=0.97, p>0.001) and the VE/VCO2-slope (r=0.60, p>0.001). Nevertheless, peak power output, peak VO2 and OUES remained significantly below the values of age-matched healthy controls (69±36%, 70±18% and 64±18% respectively).
Conclusion: HTx improves OUES and leads to an increase of peak VO2 and a decrease in the VE/VCO2-slope. Our data suggest that OUES may be used as a marker of exercise capacity during follow-up of HTx recipients; it has the advantage of unifying cardiopulmonary adaptation and peripheral muscular function in one submaximal parameter.
136 Physical exercise improves the microcirculation of patients with heart failure
V Gerovasili1; M Kravari1; L Karatzanos1; J Venetsanakos2; V Agapitou2; A Bouchla2; S Kourtidou2; ST Dimopoulos1; ST Drakos1; S Nanas2
1Cardiopulmonary Rehabilitation Center, Evgenidio Hospital, University of Athens, Greece
23rd Clinic of Cardiology, Alexandra Hospital, University of Athens, Greece
Background: Patients with chronic heart failure (CHF) present with microcirculation alterations, partially attributed to endothelial dysfunction. Aim of our study was to assess the effect of physical exercise on the microcirculation of CHF patients with the use of Near Infrared Spectroscopy (NIRS).
Methods: Sixteen consecutive CHF patients (/:10/6) (age:50±12years) participated at a 3-month rehabilitation program (3 sessions/week) consisting of aerobic training and strength training. Before the beginning and after the completion of the program patients performed a symptom-limited, ramp-incremental cardiopulmonary exercise testing (CPET) on cycle ergometer. Measurements included peak oxygen uptake (VO2p), VO2 at anaerobic threshold (AT), first degree slope of VO2 during the first minute of recovery (VO2/t slope). Tissue oxygen saturation (StO2, %) was continuously measured by NIRS at the thenar muscle before, during and after 3-min occlusion of the brachial artery via a pneumatic cuff (occlusion technique) before the beginning and after the completion of the rehabilitation program.
Results: The resaturation slope of StO2 (%/min) after the vascular occlusion increased significantly after the rehabilitation program (450 ±105%/min to 532±151%/min, p=0.004) as did the reactive hyperemia (27±13%∗min to 39±21%∗min, p=0,006). After the rehabilitation there was a significant increase at VO2peak and AT(14.3±4.7> ml/kg/min to 16.7±6.3>ml/kg/min and 9.5±3.6>ml/kg/min to 11.3±4> ml/kg/min, p=0.007 and p=0.012, respectively) as well as VO2/t slope (0.35 ±0.17 to 0.51±0.07 ml/kg/min2, p=0.005).
Discussion: The skeletal muscle microcirculation measured by NIRS improved after the rehabilitation program. NIRS is a non-invasive technique that could be used for the evaluation of the effect of rehabilitation on the peripheral microcirculation of CHF patients.
137 Effects of a three month exercise training program on muscle strength and body composition in CHF patients
A Bouchla1; L Karatzanos1; V Anagnostakou1; E Kaldara2; J Venetsanakos1; S Dimopoulos1; A Tasoulis2; M Anastasiou-Nana1; G Mansolas2; S Nanas2
1Cardiopulmonary Rehabilitation Centre, ‘Evgenidion’ Hospital, University of Athens, Greece
23rd Clinic of Cardiology, ‘Alexandra’ Hospital, University of Athens, Greece
Background: The loss of lean mass and muscle strength is a common problem in CHF patients. Exercise training, on the other hand, has been known to increase muscle mass and strength. This study seeks to evaluate the effects of strength training inclusion on muscle strength and lean mass in CHF patients.
Patients and methods: Twenty patients, 17 male and 3 female, (mean age 54±10 years, BMI 28,4±3,9) participated in a rehabilitation program for 36 sessions, three times a week for twelve weeks. Subjects were randomly assigned to aerobic (AG, n=13) or combined (aerobic plus strength, CG, n=12) training group. Aerobic training was performed in interval type on cycle ergometers. Strength training incorporated exercises for various muscle groups, including quadriceps and hamstrings. Both regimes were of the same duration. Body composition was evaluated with DXA and leg muscle strength with the sum of resistance to overcome with a two-repetition-maximum test for each leg (2-RM) before and after the program.
Results: Concerning leg lean mass, no significant within-subjects or between-groups changes were observed (p>0.05) (AG: 18137±2187 gr vs 18240±1738 gr, CG: 16504±2688 gr vs 16294±2694 gr). By contrast, both groups improved in 2-RM test (p>0.05), while a significant difference was observed between groups (p>0.05) (AG: from 36.77 ±13.42 kg to 40.15±13,77> kg, CG: from 35.16±11.68 kg to 49.08 ±16.55> kg).
Conclusion: An exercise training program can improve quadriceps strength, especially if strength training is included. Adaptations other than hypertrophy, such as muscle fiber type alterations and/or neuro-muscular adjustments, may account for these results.
138 Effects of exercise training on early recovery of pulmonary function after maximal CPET examination in CHF patients
A Georgantas1; A Tasoulis1; S Dimopoulos2; M Kravari2; L Karatzanos2; A Bouchla2; V Agapitou2; J Venetsanakos1; M Anastasiou-Nana1; S Nanas2
1Cardiopulmonary Rehabilitation Centre, ‘Evgenidion’ Hospital, University of Athens, Greece
23rd Clinic of Cardiology, ‘Alexandra’ Hospital, University of Athens, Greece
Introduction: Patients with chronic heart failure (CHF) are characterized by several central and peripheral ventilatory abnormalities that are associated with their poor prognosis. Exercise training has been shown to induce several beneficial effects in patients with chronic heart failure (CHF). However, exercise training effects on pulmonary function on early recovery in CHF patients has not been thoroughly investigated yet.
Aim: To investigate the effects of exercise effects on pulmonary function on early recovery in CHF patients.
Materials and Methods: 28 stable CHF patients 22 Male/6 Female [(54±10 yrs, VO2peak: 1.22±0.41 L/min (14.78±5.09 ml/kg/min)] participated in an exercise training program for 12 weeks, 3 times/week. Participants were randomly assigned to either aerobic (AG, n=13) or combined group (CG, n=15), which included aerobic and strength training. All participants performed a symptom-limited CPET to exhaustion at the beginning and the end of the program and pulmonary function parameters were measured during the first minutes of recovery. We calculated VO2, VCO2, Vt, T/TTOT at peak of exersice and at the first minute of recovery. We also measured the first degree slope of VO2 and VCO2, during the same period.
Results: The whole cohort increased Vtpeak (1.49±0.38 vs. 1.60±0.44 L, p>0.05) and Vt at 1st minute of recovery (1.31±0.38 vs. 1.45±0.41 L, p=0.005), VCO2peak (16.44±6.28 vs. 18.80±6.6, p>0.01) and VCO2 at the 1st minute of recovery (11.40±3.78, vs. 12.85±3,83, p>0.01) and T/TTopeak (46.7±2.77 vs. 47.96±2.8%, >0.001) and T/TTOT at the 1st minute of recovery (43.86±3.26, vs. 45.18±3.54%, p>0,05). There was no difference in FEV1 (2.53±0.78, vs. 2.6±0.85 L, ns), in FVC (3.37 ±0.79, vs. 3.46±1.09 L, ns), in respiratory rate rr (19.07±4.21, vs. 19.85 ±5.69, ns) and in tidal volume Vt at base (0.61±0.12 vs0.58±0.13 L, ns). The patients assigned to combined group (n= 15) increased the VCO2tslope (0.298±0.216, vs. 0.462 ±0.252, p>0.005), although patients to the aerobic group (n=13) decreased VCO2tslope, (0.488 ±0.313, vs. 0.416±0.238, ns) but the difference didn't reach statistical significance. All patients improved VO2peak (14.78±5.09, vs. 16.68 ±5.23 ml/kg/min, p>0.001) and VO2tslope (0.42±0.22, vs. 0.56±0.23, p>0.001).
Conclusion: Exercise training improves pulmonary function and oxygen kinetics, at peak and at the 1st minute of recovery. Especially combined exercise seems also to carbon dioxide kinetics during early recovery after CPET in CHF patients adding a further beneficial effect of exercise in CHF patients.
