Cardiac structure and function in lowlanders at high altitude:
short-term adaptation and chronic remodeling
Aims: The purpose of this study was to examine cardiac structure and
function in lowlanders at high altitude(HA) to investigate short-term
adaptation and long-term cardiac remodeling. Methods: In total of 301
healthy subjects included in this study, short-term exposed (STE) and
acclimatized lowlanders (AL) at HA, native Tibetans(NT) and sea level
residents(SLR) were comprised of 75,77,69 and 80 participants,
respectively. Standard echocardiography was performed on all groups,
subjects at HA were examined after return to sea level in <24
hours. Results: SBP and HR did not increase significantly after
short-term exposure to HA in STE, but increased after long-term exposure
in AL, which could be detected even after returning to the plain.
Exposure to HA enlarged right heart, widened pulmonary artery and
reduced left ventricular(LV) diastolic function in lowlanders. The
degree of diastolic dysfunction was more obvious in AL. LV wall
thickness increased even after short-term exposure to HA in lowlanders.
Ejection fraction did not change significantly in STE, but decreased in
AL. Conclusions: Exposure to HA could enlarged the right heart and
decrease the diastolic function of LV in lowlanders. The LV systolic
function was preserved after short-term HA exposure, but decreased after
long-term HA exposure.