Biomedical subjects

Evelyne Lonsdorfer

Publications and source records attributed to Evelyne Lonsdorfer.

3 recordsLinked to original sources

PubMed2005

Ventilation efficiency and pulmonary function after a wheelchair interval-training program in subjects with recent spinal cord injury.

OBJECTIVE: To study the effect of a wheelchair interval-training program on the ventilatory function of subjects with recent spinal cord injury (SCI). DESIGN: Evaluation trial before and after a training program. SETTING: Center of reeducation and university hospital. PARTICIPANTS: Six subjects (5 men, 1 woman) hospitalized after a recent SCI. INTERVENTION: On a wheelchair ergometer, subjects with SCI performed 30 minutes of interval training 3 times a week for 6 weeks. The training program was part of their reeducation program. MAIN OUTCOME MEASURES: Spirometric values at rest and dynamic ventilatory responses were studied before and after this training program with a spirometric test, a maximal exercise test that increased by 5W every 2 minutes, and a submaximal test. RESULTS: Spirometric values at rest did not change after training. At maximal exercise, peak ventilation (Vepeak, 7.5%), peak breathing frequency (f peak) (-13.4%), peak tidal volume (Vtpeak +28.9%), and the ventilatory reserve (12.9%) improved after training. The oxygen cost of Ve decreased significantly (-20%) after training. We observed for the wheelchair tests that, at the same workload after training, Ve and f decreased and Vt increased. CONCLUSIONS: After 6 weeks of our interval-training program in subjects with recent SCI, the increase of Vt and the decrease of oxygen cost of Ve indicated better ventilatory efficiency.

Ergometry↗

PubMed2005

Chronic but not acute oral L-arginine supplementation delays the ventilatory threshold during exercise in heart failure patients.

The purpose of this study was to determine, in heart failure patients (HF), whether acute or chronic L-arginine supplementation (LAS) might delay the ventilatory threshold (VT) and whether chronic LAS might reduce exercise-induced plasma lactate increase. HF patients undertook 4 cardiopulmonary bicycle exercises tests. The first 3 were maximal without (EX(1)), after acute (EX(2)), or chronic (EX(3)) oral LAS (6 gm twice a day for 6 weeks). The 4th test (EX(4)) performed after chronic LAS, was similar to the first in order to investigate the effect of chronic LAS on circulating lactate levels. Results showed that acute LAS failed to improve both submaximal and maximal exercise capacities. Similarly, maximal exercise capacity remained unmodified after chronic LAS. Nevertheless, chronic LAS delayed significantly the patients' ventilatory threshold. Thus exercise duration prior to VT increased (mean +/- SEM) from 6.04 +/- 0.9 to 7.7 +/- 1.03 min (p = 0.04), resulting in a significant increase in oxygen uptake (1.05 +/- 0.08 to 1.24 +/- 0.12 L.min(-1); p = 0.03), CO(2) release (0.94 +/- 0.10 to 1.2 +/- 0.12 L.min(-1); p = 0.018), minute ventilation (29.31 +/- 2.8 to 34.5 +/- 2.7 L; p = 0.009), and workload (60.7 +/- 9.8 to 78.5 +/- 10.2 watts; p = 0.034). Furthermore, chronic LAS significantly reduced the exercise-induced increase in postexercise plasma lactate concentration (-21 +/- 7%). In conclusion, unlike acute supplementation, chronic LAS significantly delays the ventilatory threshold, and chronic LAS reduces circulating plasma lactate in HF patients. These data suggest that chronic LAS might improve the ability of HF patients to perform their daily-life activities.

Anaerobic Threshold↗

PubMed2004

Improving exercise capacity, 6 wk training tends to reduce circulating endothelin after heart transplantation.

Short-term survival is no longer the pivotal issue after heart transplantation but, most heart-transplant (Htx) patients still present with increased circulating endothelin-1 (ET) and reduced exercise capacity. ET-1 limits both exercise-induced vasodilation and blood flow redistribution toward acting muscles and might be accessible to training. This study was performed to investigate the effect of training on ET-1 and whether an eventual training-induced improvement in exercise capacity may be related to reduced baseline or exercise circulating ET-1 in Htx patients. Five Htx patients performed a maximal bicycle exercise test and an endurance exercise test before and after a training program of 18 exercises sessions during 6 wk. ET-1 was determined by radioimmunoassay at rest, end endurance exercise and 30 min recovery, before and after training. Training improved significantly Htx's maximal oxygen uptake (+13.1 +/- 4.8%; p < 0.05) and also reduced significantly the endurance exercise-induced heart rate increase. Resting ET-1 was increased in Htx (5.98 +/- 1.88 vs. 1.61 +/- 0.25 pmol/L in controls; p < 0.01) but although ET-1 modulation might participate in training-induced beneficial effects, training failed to modulate either resting or exercise ET-1 plasma level. Training-induced improvement in exercise capacity might not mainly due to decreased ET-1 after heart transplantation. Further supporting the usefulness of training, these preliminary data suggest that improved exercise capacity may not be mainly due to decreased ET-1 in Htx patients. Further, larger scale studies will be needed to investigate whether an impaired nitric oxide pathway stimulation might explain such results and whether a longer training program can reduce local ET-1, arising from working muscles after heart transplantation.

Adult↗