Exaggerated pulmonary hypertension during mild exercise in chronic mountain sickness.
BACKGROUND
Chronic mountain sickness (CMS) is an important public health problem and is characterized by exaggerated hypoxemia, erythrocytosis, and pulmonary hypertension. While pulmonary hypertension is a leading cause of morbidity and mortality in patients with CMS, it is relatively mild and its underlying mechanisms are not known. We speculated that during mild exercise associated with daily activities, pulmonary hypertension in CMS is much more pronounced.


METHODS
We estimated pulmonary artery pressure by using echocardiography at rest and during mild bicycle exercise at 50 W in 30 male patients with CMS and 32 age-matched, healthy control subjects who were born and living at an altitude of 3,600 m.


RESULTS
The modest, albeit significant difference of the systolic right-ventricular-to-right-atrial pressure gradient between patients with CMS and controls at rest (30.3 +/- 8.0 vs 25.4 +/- 4.5 mm Hg, P 5 .002) became more than three times larger during mild bicycle exercise (56.4 +/- 19.0 vs 39.8 +/- 8.0 mm Hg, P < .001).


CONCLUSIONS
Measurements of pulmonary artery pressure at rest greatly underestimate pulmonary artery pressure during daily activity in patients with CMS. The marked pulmonary hypertension during mild exercise associated with daily activity may explain why this problem is a leading cause of morbidity and mortality in patients with CMS.
University Hospital of Bern, Cardiology, Bern, Switzerland.
Thomas
T
Stuber
Claudio
C
Sartori
Marcos
M
Schwab
Pierre-Yves
PY
Jayet
Stefano F
SF
Rimoldi
Sophie
S
Garcin
Sébastien
S
Thalmann
Hilde
H
Spielvogel
Carlos Salinas
CS
Salmòn
Mercedes
M
Villena
Urs
U
Scherrer
Yves
Y
Allemann
D000532:Altitude Sickness / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology; D001838:Bolivia / Q000453:epidemiology; D002908:Chronic Disease; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009017:Morbidity / Q000639:trends; D011379:Prognosis; D011669:Pulmonary Wedge Pressure / Q000502:physiology*; D015996:Survival Rate / Q000639:trends