240
Dynamics
of
the
kp&
CONTROL
kN
IF
NDF
Vascular
System
IAEP
CONTROL
IAW
Fig.
8.2.2:
Intra-aortic balloon pumping
(IABP)
efficacy
on
segmental cardiac muscle
shortening, coronary blood flow (CBF) and aortic flow. Top: normal inflation
@TIF)
and
normal deflation
(NDF)
of
the balloon when nitrogen
(N2)
is
used as the driving gas.
Bottom:
same,
except helium
(He)
is
used as the driving gas. It
is
clear that in both cases,
IABP
greatly improved coronary blood flow, muscle shortening and aortic flow through
proper timing of diastolic aortic pressure augmentation.
LN
and
LB
are segment lengths.
Pa,
=aortic pressure, Q,,=aortic flow,
PL\rleft
ventricular pressure.
