3 Clinical Trials for Various Conditions
In summary, the investigators propose to study elite Croatian breath-hold and SCUBA divers. The investigators will quantify breath-hold hypoxia- and SCUBA diving-induced pulmonary hypertension and right heart function to investigate the relationships between PFO and IPAVA blood flow. The investigators will use a placebo-controlled intervention (sildenafil) to reduce pulmonary arterial pressure in these subjects to examine the impact of the change in pressure (or absence of change) on the relationships determined above.
The purpose of this study is to determine the impact of high intensity,anaerobic exercise, in the form of cycling, on SCUBA diving. Outcomes are determined by the quantification and subtype of circulating microparticles, complete blood counts, and the quantification of venous gas emboli, measured via transthoracic echocardiography, in the cardiac cavities.
SCUBA diving frequently involves repetitive exposures over multiple days. The goal of this study was to see how exercise impacts microparticles (MPs), endothelial function, and venous gas emboli (VGE) over a series of dives. 16 divers in 2 groups each completed 6 dives. One group completed 3 control dives followed by 5 days rest then 3 dives preceded by exercise. The other group completed the opposite protocol. Flow-mediated dilation (FMD) data and blood for MP analysis was collected before and after each dive. VGE were monitored via transthoracic echocardiography 30, 60, and 90 min after surfacing. Exercise before diving consisted of 60 min running outdoors including 8x4 min intervals at 90% VO2max effort.