QUEBEC CITY, Oct. 21 /CNW Telbec/ - An expedition of Canadian
cardiologists and researchers to the Andes goes to the heart of the most
pressing issue in mountaineering medicine.
Can simple blood tests be developed that will tell who is at risk of
developing altitude sickness (hypoxia) before disabling symptoms appear?
Dr. Patrick Garceau of Laval Hospital described to the Canadian
Cardiovascular Congress preliminary results from an expedition that ascended
Huyana Potosi (6,088 meters above sea level) in Bolivia in search of some
The Congress is co-hosted by the Heart and Stroke Foundation and the
Canadian Cardiovascular Society.
Dr. Garceau brought with him an echocardiogram, the size of a lap-top
computer, to look at general heart function.
Dr. Garceau's climbing cardiology laboratory demonstrated that right
ventricular abnormalities seem to be responsible for the reduced exercise
performance of climbers at high altitudes. "Our echocardiographic measurements
showed the left part of the heart is working normally but the right is
impaired," said Dr. Garceau.
"Physical activity is one of the best things you can do for your heart
health," says Heart and Stoke Foundation spokesperson Dr. Beth Abramson. "But
unlike the daily physical activity we encourage all Canadians to participate
in, mountaineering has unique risks. This study reminds us that we need to
take precautions to prevent disaster."
In addition, Dr. Garceau measured blood levels of brain natriuretic
peptide (BNP), a hormone that the heart releases when stressed. He believes
that if BNP levels correlate with the echocardiogram abnormalities, the way is
open for a simple blood test to screen out climbers who are not yet ready for
high altitude activities.
Dr. Garceau is preparing data on this for a soon-to-be published paper.
The expedition consisted of three cardiologists and 12 researchers (eight
men and four women) and 22 porters. Intensive cardiac testing was carried out
on expedition members at baseline (353 meters) first camp (4,000 meters)
second camp (4,750 meters) and high camp (5,300 meters.)
"Unfortunately, we found that we could not make our way to the summit
because global warming was making the ice too treacherous," said Dr. Garceau.
"We opted for 5,300 meters, which is higher than the base camp for Everest."
Two members of the expedition developed pulmonary hypertension and one
had to take medication to improve his clinical status
"We proved that some patients present with right diastolic heart failure
- a relaxation of the heart that might become abnormal. Although we measured
BNP at the time, we haven't finished comparing it to heart function, "said
Dr. Garceau. "We think that the diastolic dysfunction we measured in the
mountains in the right ventricle might increase the BNPs."
"If we correlate this with BNP measurement, the idea is that anyone who
wants to go to Everest can be tested for BNP with one blood sample. If BNP
levels are up, the person may not be fit enough to make the climb, and may
have to wait for a few days of acclimatization before making their ascent."
"If these results work out, a simple test could help identify climbers
who are not fit to climb, and could save lives," said Dr. Abramson of the
Heart and Stroke Foundation. "We all need to be aware of our fitness levels,
whether we are climbing mountains or not."
Video footage and illustrations are available to the media.
Statements and conclusions of study authors are solely those of the study
authors and do not necessarily reflect Foundation policy or position. The
Heart and Stroke Foundation of Canada makes no representation or warranty as
to their accuracy or reliability.
The Heart and Stroke Foundation (www.heartandstroke.ca), a
volunteer-based health charity, leads in eliminating heart disease and stroke
and reducing their impact through the advancement of research and its
application, the promotion of healthy living, and advocacy.
For further information:
For further information: and/or interviews, contact the CCC 2007 MEDIA
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