CareFusion PulseTrace PCA2 Manual Operativo página 32

When the amplitude of the reflected wave
'
increases and/or the reflected wave arrives
'
earlier during the cardiac cycle, the diastolic
peak is only visible as an inflection point.
This is the most common waveform observed
in a middle aged subject. The inflection
point can sometimes be too small to be clearly visible. If unsure
about the presence of an inflection point, the measurement should
be repeated. Sublingual GTN can be administered to relax the
smooth muscle in the arterial wall. This decrease in arterial stiffness
and vascular tone will normally improve the waveform and allow a
measurement to be made reflecting a base-line state.
With further increase in amplitude of the
'
reflected wave and/or its earlier arrival
' '
during the cardiac cycle, the direct wave and
the reflected wave may produce an "extra
bump" bigger than the direct wave as shown
on the adjacent graph.
In this case, RI is calculated from the
nd rd
diastolic peak and systolic peak (2 and 3 marker). However, PPT
and SI are calculated from the early systolic peak to the diastolic
st rd
peak (1 to 3 marker).
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