"Swimming induced pulmonary edema (SIPE), a form of high output heart failure. The physiology involves a pooling of the body's blood into the core, and when there is an overload of blood circulation in the core, the weakest link is usually the lung's capillaries so the blood leaks into there. the risk then is of a deprivation of oxygen supply that causes cardiac arrest.
Im sharing this because i think it's really important for triathletes to understand this "high output heart failure" which has an unusual incidence in triathletes and results from this perfect storm of some or all of the following variables that are independent of your fitness/training.
- use of wetsuit - adds additional extrinsic compression to the extremities that shunts blood up to the core. here, i blame the NY ironman's poor logistics as this was further exacerbated by the fact that we had to wear the wetsuit for 2 hours leading up to the swim.
- temperature of water - causes blood to pool into core and out of extremities to keep body warm (cold is anything below body temperature, so don't think this only applies in freezing water)
- pressure of water - water exerts a much larger force on bodily tissues than air does, and the increased pressure forces blood from the skin, muscle, fat etc into the vessels/circulatory system
- pre-race adrenalin - increases cardiac output AND constricts blood vessels moving blood toward core
- hydration - increases the volume of blood cells
Basically it doesn't matter if you are in great shape, new, veteran, or not. We are all possibly at risk of this cardiac problem because of environmental factors it seems.
I am not a doctor or expert - just opening grounds for a discussion.
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