Inter-limb changes in arterial function after intense cycling exercise.

We investigated whether muscle exercise, by inducing a subsequent local response, alters local and systemic arterial function differently. Eleven healthy volunteers (31±8 years) performed a 45-min cycling session at a heart rate corresponding to 10% above ventilatory threshold. Measurements were performed before and 45 min after exercise. Central and peripheral blood pressures were assessed by applanation tonometry and automatic sphygmomanometer, respectively. Brachial and popliteal arterial changes in diameter and blood flow were assessed using ultrasonography. The endothelium-dependent function was assessed simultaneously on brachial and popliteal arteries by flow-mediated dilation. Systolic blood pressure decreased significantly in both upper and lower limbs as well as centrally. Ankle-brachial index decreased significantly. Cross-sectional area and blood flow of popliteal and brachial arteries increased significantly. The increase in blood flow was higher in the brachial than in the popliteal artery, whereas diameter increase was of similar magnitude between the two arteries. When normalized with shear rate, brachial flow-mediated dilation was significantly greater, whereas popliteal flow-mediated dilation was similar post- vs. pre-exercise. After an acute bout of intense cycling, blood flow increase and endothelial function were greater in the non-exercised upper limb compared to the exercised lower limb, suggesting that anaerobic exercise blunts the enhancement of systemic endothelium-dependant vasodilation in active muscle beds.

Cardiac alterations induced by a fish-catching diving competition.

Cardiac changes induced by repeated breath-hold diving were investigated after a fish-catching diving competition. Eleven healthy subjects carried out repeated breath-hold dives at a mean maximal depth of 20 ± 2.7 msw (66 ± 9 fsw) during 5 h. One hour after the competition, the body mass loss was -1.7 ± 0.5 kg. Most of the breath-hold divers suffered from cold and although the core temperature remained normal, a decrease in cutaneous temperature was recorded in the extremities. Systolic blood pressure was reduced in both upper and lower limbs. Heart rate was unchanged, but left ventricular (LV) stroke volume was reduced leading to a decrease in cardiac output (-20%). Left atrial and LV diameters were significantly decreased. LV filling was assessed on a trans-mitral profile. An increase in the contribution of the atrial contraction to LV filling was observed. Right cavity diameters were increased. The cardiac autonomic alterations were in favor of sympathetic hyperactivity. After a fish-catching diving competition in cold water, alterations suggesting dehydration, contraction in plasma volume and sympathetic hyperactivity were observed. Furthermore, enlargements of right cavities were in favor of right ventricular strains. Repeated apnea and swimming in cold water may account for these alterations.

Ultrasound lung comets induced by repeated breath-hold diving, a study in underwater fishermen.

Pulmonary edema has been reported in breath-hold divers during fish-catching diving activity. The present study was designed to detect possible increases in extravascular lung water (EVLW) in underwater fishermen after a competition. Thirty healthy subjects were studied. They participated in two different 5-h fish-catching diving competitions: one organized in the winter (10 subjects) and one organized in the autumn (20 subjects). A questionnaire was used to record underwater activity and note respiratory problems. An increase in EVLW was investigated from the detection of ultrasound lung comets (ULC) by chest ultrasonography. Complementary investigations included echocardiography and pulmonary function testing. An increase in EVLW was detected in three out of 30 underwater fishermen after the competition. No signs of cardiovascular dysfunction were found in the entire population and in divers with an increase in the ULC score. Two divers with raised ULC presented respiratory disorders such as cough or shortness of breath. Impairment in spirometric parameters was recorded in these subjects. An increase in EVLW could be observed after a fish-catching diving competition in three out of 30 underwater fishermen. In two subjects, it was related to respiratory disorders and impairment in pulmonary flow.

Pulmonary oedema in healthy SCUBA divers: new physiopathological pathways.

INTRODUCTION: The mechanism of immersion pulmonary oedema occurring in healthy divers is a matter of debate. Among consecutive injured divers admitted to our hyperbaric centre, we analysed prospective data about pulmonary oedema. METHOD: A total of 22 divers suffering from immersion pulmonary oedema without cardiac disease were included. The occurrence of events was compared to the diving conditions as assessed by diving-computer. Each patient underwent a clinical examination, laboratory tests, thoracic CT scan and echocardiography. RESULTS: The median age was 49 years, with a higher proportion of women, in comparison with the data of the French diving federation. The common feature was the occurrence of respiratory symptoms during the ascent after median dive duration of 29 min with strenuous exercise and/or psychological stress. Most of the dives were deep (37 msw-121 fsw) in cool water (15 degrees C-59 degrees F). The average inspired oxygen partial pressure was 0.99 bar. Progression was rapidly favourable, and the medical check-up after clinical recovery was normal. CONCLUSION: Immersion, body cooling, hyperoxia, increased hydrostatic pressure and strenuous exercise likely combine to induce pulmonary oedema in patients without cardiac disease. This study underlines new physiopathological tracks related to the frequent occurrence of symptoms noticed in the last part of the ascent and a higher incidence in women.