Venous gas emboli are involved in post-dive macro, but not microvascular dysfunction

Area of Science:

• Physiology
• Cardiovascular Science
• Diving Medicine

Background:

• Previous research indicates diving impairs vascular function in both large arteries and small vessels.
• Bubble formation is a known consequence of diving and may contribute to vascular dysfunction.

Purpose of the Study:

• To investigate the impact of vibration preconditioning on bubble formation and subsequent vascular function and hemostasis after diving.
• To determine if reducing bubble load through vibration mitigates diving-induced vascular impairments.

Main Methods:

• Twenty-six divers were divided into three groups: vibration-dive, diving only, and vibration only.
• Macro- and microvascular function, bubble grades, platelet function, and endothelial function were assessed before and after protocols.
• Whole-body vibration was applied 30 minutes prior to diving in the vibration-dive group.

Main Results:

• The vibration-dive group exhibited lower bubble formation compared to the diving-only group.
• Diving alone led to macrovascular dysfunction, increased procoagulant microparticles (PMP), and thrombin generation, which were prevented by vibration preconditioning.
• Microvascular dysfunction remained even with reduced bubble load in the vibration-dive group.

Conclusions:

• Vibration preconditioning effectively reduces bubble formation and prevents macrovascular dysfunction after diving.
• Bubbles appear to be a significant factor in macrovascular impairment, potentially through platelet activation and PMP generation.
• Microvascular dysfunction after diving is not solely attributable to bubble load and warrants further investigation.