 Diving
Diving can affect the heart both by the amount of exercise
stress involved and by a series of factors specific to diving.
Scuba diving is associated with changes in blood pressure, oxygen
concentration and body temperature. This can affect the amount of
blood returning to the heart (“Preload”) and the constriction of
the small arteries in the bowel and limbs (“Afterload”).
In addition, an increase in hydrostatic pressure can affect the
electrical conduction pathways of the heart. A unique feature of
scuba diving is the potential to develop gaseous bubbles in the
blood stream during decompression. If there is a small hole
between the top chambers of the heart (“Patent Foramen Ovale”)
this can allow bubbles to cross into the main systemic
circulation.
A cardiology
advice service including screening for Patent Foramen Ovale can be
carried out by Sports Cardiology UK.
Click here for link to Video of the PFO screening test
(video coming soon)
A small plastic tube is inserted into a hand vein and a fluid
injection is given. The fluid injection contains microbubbles
which appear as an opaque region within the heart. In this patient
there is a Patent Foramen Ovale (PFO). During a deep breathe,
bubbles are seen crossing the PFO from left to right in the lower
part of the screen. These bubbles can then pass round the systemic
circulation. Normally, any microbubbles are filtered out in the
lungs. In the diving situation, the presence of a PFO can lead to
a systemic bend. In most cases, it is possible to close a PFO
using a minor keyhole operation. Sports Cardiology UK have close
links with an expert interventional cardiology team who can carry
this out.
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