Page 22 - AlertDiver_Spring2013

DIVE SLATE //
20 | SPRING 2013
As people live longer,
they participate longer
in recreational sports.
Scuba diving sees its
share of older participants as both
veterans and beginner divers. As
happens in other recreational
activities, such as golf and jogging,
some divers die of cardiac events
while diving. However, since diving
involves immersion, which requires
adaptation of divers’ hearts and
cardiovascular systems, there is a
possibility that it may cause more
deaths than would naturally occur
out of the water. Fatalities are rare
in diving, but they increase with
diver age, and cardiac causes are of
particular concern in older divers.
Most of the deaths in older divers
that result from cardiovascular
causes are unexpected sudden
cardiac deaths (SCD), which occur
in divers who felt well before the
dive. These cardiac events cause up
to 400,000 deaths in the U.S. each
year; in half of these cases SCD
is associated with obvious heart
disease, but in the other half it
occurs in apparently healthy people,
which makes prevention difficult.
One risk factor associated with
SCD is abnormal thickness of the
left heart wall, which is known as left
ventricular hypertrophy (LVH). This
condition occurs when the heart has
to work against increased resistance
as it does, for example, in people
who have high blood pressure. (Not
all people with high blood pressure
develop LVH, and, fortunately, LVH
may even resolve when high blood
pressure is effectively treated.) The
prevalence of LVH in the general
population is about 15 percent,
but most of those who have it are
unaware because symptoms occur
only in the most severe cases.
LVH sometimes causes such bad
heart rhythms that the heart does
not pump enough blood and the
affected person loses consciousness.
Confronting
Cardiovascular
Hazards
DAN Research targets left
ventricular hypertrophy
in divers.
Get
Involved
If members of
your dive-club- or
dive-shop-
organized trip
are interested in
participating in this
study, please call
Jeanette Moore
at +1-919-684-
2948, ext. 260.
A researcher uses
echocardiography to observe
a diver’s heart after a dive.
Opposite: Electrodes are placed
on a diver to monitor the electrical
activity of his heart during a dive.
Jennifer O’Neill
800-328-2288
Specific dates for travel required. Blackout dates, holiday
surcharges and other restrictions may apply. Rates may be
subject to change. (CSOT # 2111993-40, WASOT
#603254639 & Fla. Seller of Travel Ref. No. ST38781)
WWW. CARADONNA . COM
Super
Savings
Bonaire
STEPHEN FRINK