[Case report: chronic cough]. / Histoire d'une toux chronique.

A 64 years old woman was admitted for persistent dry cough. The cough was lasting for one month and was associated with throat clearing, asthenia and low fever mainly at night. A thorough anamnesis also revealed the existence of mild occipital headache. Empirical antibiotic therapy (clarithromycine) had previously been administered without any clinical improvement. Physical examination was normal. However, the blood tests showed an inflammatory syndrome. The diagnostic approach was focused on the lungs, sinuses and digestive tract and did not show any acute disease. The bronchoscopy demonstrated an edematous bronchial mucosa without endoluminal lesion. The results of bacteriological tests performed were negative. Given the age of the patient and the persistence of an inflammatory syndrome of unknown origin, the diagnosis of giant cell arteritis should be excluded, despite an unusual clinical presentation. This hypothesis was supported by a diagnostic biopsy of the right temporal artery, which histological analysis showed characteristic pattern.

VO2 slow component is independent from critical power.

The aim of this study was to determine whether the amplitude of the V˙O (2) slow component was dependent from Critical Power (CP; the slope of the linear time - distance relationship) in individuals matched for V˙O (2) peak. 30 moderately-trained endurance athletes completed a maximal graded exercise test, 2 randomly ordered constant power tests at 90 and 100% of peak power output (PPO), and 2 constant duration test of 6 min at 30% of the difference between CP and PPO. Afterwards, participants were ranked according to their relative CP (%PPO; a direct measure of aerobic endurance). The median third was excluded to form a low aerobic endurance group (LEG) and a high aerobic endurance group (HEG). A t-test revealed no difference between LEG and HEG in peak oxygen consumption, but a large difference in their relative CP (p<0.001, effect size=3.2). A' (2) was similar between groups (626 ± 96 and 512 ± 176 ml, corresponding to 26 ± 4 and 24 ± 8% of end exercise oxygen consumption, respectively; NS) and was not associated with relative CP (r=0.10; NS). These results suggest that increasing CP probably extends the range of exercise intensities over which the V˙O (2) slow component does not develop, but does not decrease the amplitude of this phenomenon once it occurs.

Digoxin increases peripheral chemosensitivity and the ventilatory response to exercise in normal subjects.

1. The contribution of peripheral chemoreceptors to the regulation of ventilation during exercise remains incompletely understood. Digoxin has been reported to increase chemoreflex sensitivity in humans. In the present randomized, cross-over, double-blind study, we tested the hypothesis that this increases the ventilatory response to exercise in normal subjects, as assessed by changes in minute ventilation (V(E)) in response to the rate of CO(2) production (VCO(2)). 2. Minute ventilation, end-tidal PCO(2), pulse oximetric O(2) saturation (S(p)O(2)), heart rate and blood pressure (BP) were measured in 11 healthy young male untrained subjects after intravenous infusion of digoxin (0.01 mg/kg) or placebo during normoxia, isocapnic hypoxia and hyperoxic hypercapnoea. All participants underwent a maximum cardiopulmonary exercise test. 3. During normoxia, digoxin increased systolic BP only. During hypoxia, digoxin increased V(E) compared with placebo (P = 0.009) for the same fall in S(p)O(2) (P = NS). Moreover, no significant effects on ventilation and haemodynamic responses were recorded during hypercapnoea. Digoxin increased the V(E) /VCO(2) slope above the anaerobic threshold from 30.4 +/- 2.9 to 32.8 +/- 3.7 (P < 0.05), but did not affect VO(2max). 4. In conclusion, enhanced peripheral chemosensitivity with digoxin increases the ventilatory response to CO(2) production above the anaerobic threshold, but does not affect exercise capacity in healthy humans.