Hemodynamics
of
Large Arteries
89
and Li,
1992).
The developing arterial elastance at systole reflects the
time-varying compliance characteristics that are associated with active
tension development of the arterial wall, as established for the ventricular
muscle. This also demonstrates that the interaction of the heart and the
arterial system is a dynamic one, particularly in systole. The arterial
compliance thus bears a temporal, hence dynamic, relation to left
ventricular function.
2.9r
-?
5
......
n
c'
... -.,
-
E
3
2.8
-
r
E
0,
-9
a
v
0
Q)
2.6
0
*J
.u
v)
0
-
Eos(t)
-
3
::
Ej
_.....
-
>
X
2.5
....-
I.
Eyt)
-
-0
2*i.00
.
0.04
.
0.08
'
0.;2
.
0.;6
.
0.20
-I
...
4
time
(sec)
Fig.
4.1.8:
Temporal relation of time-varying
left
ventricular and arterial system
elastances, demonstrating the dynamic interaction during systole. Arterial system
elastance is obtained from the pressure-dependent compliance (E,,(t)
=
l/C(P)).
4.2
Pressure-Flow Relations and Vascular Impedance
4.2.
I
Pressure and
Flow
Waveforms in Large and Small Arteries
Pressure and flow waveforms in different anatomic locations in the
vascular system owe to their structural and geometric nonuniformities, as
well as central and peripheral interactions.
Simultaneous recordings of
pressure and flow waveforms in different parts of the vascular tree have
shown some distinct features as the pulse travels away from the heart.
