Download Comparison of Volume Displacement During Heart Rate Changes

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11.5.2002
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N T E R N A T I O N A L
IABP system analysis
Comparison of
Volume Displacement
During Heart Rate
Changes
Intra-aortic balloon counterpulsation
(IABP) is the most frequently employed
method of assistance for patients with left
ventricular (LV) failure. Over 125,000
intra-aortic balloons (IAB) are placed
worldwide annually. Although the IABP is
an adjunctive rather than primary
therapy, many studies have shown that
counterpulsation has a positive impact on
patient outcome.
The effectiveness of IABP is determined by
several factors such as IAB size relative to
the aorta (occlusivity), ability to track
arrhythmias, speed of inflation and
deflation and proper timing of IAB
inflation and deflation within the cardiac
cycle. While speed is important, the ability
to displace volume is the actual event
which determines the effectiveness of
augmentation and unloading. The purpose
of this test is to quantify the impact of
heart rate (HR) changes (increases) on
volume displacement by the IAB.
Methods: Experiments were performed using
the TMS (Test Measurement System, Arrow
International, Everett, MA.) This system
is a heated water bath with the ability to
measure IAB/IABP performance
parameters. These measurements include
inflation/deflation speed and total volume
displaced by the IAB. This system is used to
provide data for FDA 510(k) regulatory
review. Data was collected on a standard PC
via a data acquisition card at 250Hz. Data
was imported into Excel for storage and
graphing.
Data collection was commenced and the
HR on the simulator was increased from
80 bpm to 120 bpm and from 80 to 130
bpm. No changes were made to any of the
IABP console settings. The results were
recorded and compared.
Test protocol: An Arrow IAB-05840U was
used for all tests. The same IAB was
compared on 3 different IABP systems, the
Arrow ACAT® 1 PLUS, Arrow AutoCAT™,
and the Datascope® System 98. All IABP
systems were operating in their latest
configuration. The test was performed under
standard FDA 510(k) measurement
conditions. These include bath heat 98.6
degrees (37ºC) and a system pressure at
midpoint of the IAB 75 mmHg.
Trace 3: AP waveform
The IAB was connected to each IABP
console as recommended by Arrow
International instructions for use, using the
standard driveline tubing included in the
IAB packaging. Each IABP console was
connected to the IAT-00201 Interactive
Simulator as specified in each operator’s
manual.
The HR was set to 80 bpm and timing was set
per manufacturer’s instructions. Purge or
fill cycles were instituted on all pumps to
ensure optimal performance of each IABP
system, as per manufacturer’s instructions.
Summary of Results: Data from each
IABP console was recorded. The following
4 traces are shown on the graphs:
Trace 1: Inflate/Deflate commands
(Assist Marker)
Trace 2: ECG waveform
Trace 4: Volume displacement curve
The ACAT® 1 PLUS and the AutoCAT™
volume displacement dropped slightly
after the initial increase in HR to an
average of 40.2cc and 36cc at a HR of 120
and 39.1cc and 36.3cc at a HR of 130,
respectively. Volume displacement was
within the acceptable range of +/- 10% of
actual IAB size.
The Datascope® System 98 displaced an
average volume of 38.3cc at 80 bpm. When
the HR was increased to 120 bpm, the
displaced volume dropped to an average of
26cc, a 35% reduction. When the HR was
increased from 80 to 130 bpm, the
displaced volume decreased to an average
of 19cc, a 52% reduction.
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Conclusion: Which would
you rather have 15m sec
(11%) faster deflation or
14 to 20cc (35-50%) more
volume? The Arrow IABP
systems (ACAT ® 1 PLUS
and AutoCAT™) provided
more volume displacement
with heart rate increases
from 80 to 120 bpm and 80 to
130 bpm. This would
improve hemodynamic
support under this type of
clinical condition.
For information regarding distribution
in your area, contact:
www.arrowintl.com
©2002 Arrow International, Inc. All rights reserved.
Datascope® is a registered trademark of Datascope, Inc.
ISA1-M 5/02 6M