112
Dynamics
of
the Vascular System
Similarly,
resolution of flow into its forward
components can be obtained from
a
set of
two
equations:
Q,
=
(Q+
PIZo)/2
Q,.
=(Q-P/Zo)/2
...........
......
...
..................
.-::::
.......
CONTROL
and reflected
(4.4.7)
(4.4.8)
Fig.
4.4.1:
Simultaneously recorded ascending aortic pressure and
flow
waveforms
during control (left), methoximaine induced vasoconstriction (middle) and nitroprusside
induced vasodilation (right).
From the above equations, it can be seen that wave reflection has
opposite effects on pressure and flow.
An increase in wave reflection
increases the pressure amplitude, but decreases the flow amplitude. This
is
particularly evident during different vasoactive states.
Fig. 4.4.1
illustrates the pressure and flow waveforms recorded during control,
