Weightlessness during long-term space flight over
6-12 months leads to complex individual
cardiovascular adaptation. The initial central
blood volume expansion followed by a loss of
plasma volume is accompanied by changes in
vascular mechanoreceptor loads and
responsive-ness, altered autonomic reflex control
of heart rate and blood pressure, and hormonal
changes in the long run. Hence, function and
structure of the heart and blood vessels may
change. Hemodynamic data obtained during
short- and long-term space flight may indicate
that the adaptation process resembles ageing of
the cardiovascular system characterized by
decreased diastolic blood pressure, increased
central sympathetic nerve traffic and increased
arterial pulse wave velocity. Experiments during
parabolic flights in supine position suggest, that
stroke volume does not change during transitions
between µ-g and 1-g.
We tested a novel method of pulse wave
separation based on simple oscillometric brachial
cuff waveform reading to investigate pulse wave
reflection during acute weightlessness in healthy
subjects. We hypothesized that the wave
reflection magnitude (RM) remains unaltered
during parabolic flights in supine position
