Pulmonary Artery Pressure in Ladakhi Men on Exposure to Acute
Hypoxia after a Stay at Sea Level
C. V.
Apte
Officer
in Charge,
High
Altitude Medical Research Centre,
Leh,
Ladakh, India
( Received on Dec 12, 2003)
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Abstract : We had observed that very few Ladakhi soldiers
(native highlanders : NHL) are hospitalized for high altitude
pulmonary oedema. We hypothesized that this may happen because
pulmonary artery pressures of NHLs do not increase even after
exposure to acute hypoxia. The aim of this study was to test the
above hypothesis by non-invasive echocardiographic assessment of
pulmonary arterial pressure in freshly inducted Ladakhi soldiers
and comparing it with that in freshly inducted lowlander soldiers
(LL). The pre-ejection period and acceleration time ratio as
measured from the pulmonary artery Doppler signal was used to
compute mean pulmonary arterial pressure. In NHL this pressure on
day 1 of induction was significantly lower at 25.8 ± 6.5 mmHg as
compared to 31.9 ± 9.5 mmHg in LL (P = 0.0002). Another finding of
interest was the very low Lake Louise acute mountain sickness
score in the NHL (0.278 ± 0.461 on day 2). This appears to be
further evidence that the natives of Ladakh are adapted to hypoxia
and not merely acclimatized.
Key words :
altitude
adaptation
echocardiography
hypoxia
vasoconstriction
Ladakh
