INTRA-AORTIC BALLOON COUNTERPULSATION
Dr. VISHAL VANANI
JASLOK HOSPITAL AND RESEARCH CENTRE
augmentation of coronary blood
flow by retardation of the arterial
pressure pulse in animal models
In 1958, Harken suggested the
removal of some of the blood
volume via the femoral artery
during systole and replacing it
rapidly in diastole as a treatment
for left ventricular (LV) failure, so
called diastolic augmentation.
In the 1960s, Moulopoulos and
colleagues from the Cleveland Clinic
developed an experimental prototype
of an IABP whose inflation and deflation
were timed to the cardiac cycle.
In 1968, Kantrowitz reported improved
systemic arterial pressure and urine
output with the use of an IABP in two
subjects with cardiogenic shock, one of
who survived to hospital discharge.
Balloon catheters were 15 French and needed
to be surgically grafted into the femoral arteries.
Percutaneous IABs in sizes 8.5-9.5 French (rather
than 15 French used earlier) were introduced in
1979, and shortly after this, Bergman and
colleagues described the first percutaneous
insertion of IABP.
The first prefolded IAB was developed in 1986.
Preload refers to the amount of stretch on the
ventricular myocardium prior to contraction.
Starling’s law described how an increase of volume
in the ventricle at the end of diastole resulted in an
increase in the volume of blood pumped out.
Preload is often referred to as “filling pressure”.
Factors affecting preload include:
Circulating blood volume
Mitral valve disease
Some medications (i.e. Vasoconstrictors, vasodilators)
Afterload is the resistance that the heart must overcome in
order to eject the blood volume from the left ventricle
Afterload takes several forms:
The mass of blood that must be moved, measured by the
Aortic end diastolic pressure (AEDP).
Afterload can be affected by:
Arterial vasoconstrictors and vasodilators
Peripheral arterial constriction
IABP – HOW IT WORKS
A flexibile catheter – into the descending aorta.
Correct positioning – Important
When inflated, the balloon blocks 85-90% of the aorta.
This balloon displaces the blood that is in the aorta.
This is known as counter pulsation
This sudden inflation moves blood superiorly and inferiorly
to the balloon.
When the balloon is suddenly deflated, the pressure
within the aorta drops quickly.
IABP – HOW IT HELPS
Inflation of the balloon occurs at the onset of
At that point, maximum aortic blood volume is
available for displacement because the left ventricle
has just finished contracting and is beginning to
relax, and the aortic valve is closed.
The pressure wave that is created by inflation forces
blood superiorly into the coronary arteries.
This helps perfuse the heart.
Blood is also forced inferiorly increasing perfusion to
distal organs (brain, kidneys, tissues, etc.)
The balloon remains inflated
At the onset of systole, the balloon
is rapidly deflated. The sudden loss
of aortic pressure caused by the
deflation reduces afterload.
The left ventricle does not have to
generate as much pressure to
achieve ejection since the blood
has been forced from the aorta.
This lower ejection pressure reduces
the amount of work the heart has to
do resulting in lower myocardial
Femoral cut down
The IABP device has two major components:
1. A double-lumen 8.0-9.5 French catheter with a 25-50 ml
balloon attached at its distal end; and
2. A console with a pump to drive the balloon.
The balloon is made of polyethylene and is inflated with
gas driven by the pump.
The end of the balloon should be just distal to the takeoff
of the left subclavian artery
Position should be confirmed by fluoroscopy or chest x-
Tracks cardiac cycle, cardiac rhythm
and adjusts automatically
Operator must adjust inflation &
Operator must adjust inflation &
deflation & can set fixed rate
• During a cardiac arrest, the IABP can
provide very effective perfusion in
conjunction with external compressions.
• Since there is no ECG signal and no arterial
pressure wave to trigger the pump, an
internal trigger is selected.
• This trigger detects the flow of blood caused
by compressions and inflates the balloon
providing improved circulation.
• Good, consistent compressions are a must
for this to work!
Timing of inflation:
• First identify the dicrotic notch (when the aortic valve
If inflation is too early the balloon inflates before the
aortic valve closes and pumps blood backwards into
the LV, and ↑ LVEDV & LVEDP, Increased left ventricular
wall stress or afterload, Aortic regurgitation, Increased
• If inflation is too late there will be sup-optimal coronary
Timing of deflation:
• If deflation is too early there will be inadequate afterload
reduction and sub-optimal coronary perfusion
• If deflation is too late the balloon remains inflated too
long, causing ↑ afterload because the heart is trying to
pump against an inflated balloon
Assisted aortic end diastolic pressure may be ≤ the
unassisted aortic end diastolic pressure.
Assisted systolic pressure may rise.
Sub-optimal coronary perfusion.
Potential for retrograde coronary and carotid blood
Sub-optimal after load reduction & Increased MV02
Assisted aortic end diastolic pressure may be equal to
the unassisted aortic end diastolic pressure.
Rate of rise of assisted systole is prolonged.
Diastolic augmentation may appear widened.
Afterload reduction is essentially absent.
Increased MV02 consumption due to
The left ventricle ejecting against a greater resistance
IAB may impede left ventricular ejection and increase
Ankle flexion and extension one to two hourly
Use pressure relieving mattress
Change ECG electrodes daily.
Change occlusive dressing daily
Secure balloon catheter at several points
along the limb.
Observe hourly at catheter insertion site
For signs of bleeding
Signs of infection
Signs of blood in sheath
If blood or brown dust is observed within the
lumen, immediately place the IABP on
The catheter will have to be removed
Check hourly for left radial pulse
Put SaO2 probe on left hand
Assess the limb distal to the insertion
One hourly Observe and record peripheral
pulses, capillary refill, skin, temperature
Observe the waveform to ascertain that the
timing is correct
WEANING of IABP
Timing of weaning
Patient should be stable for 24-48 hours
Decreasing inotropic support
Decreasing pump ratio
From 1:1 to 1:2 or 1:3
Monitor patient closely
If patient becomes unstable, weaning should
be immediately discontinued
Discontinue heparin six hours prior
Check platelets and coagulation factors
Deflate the balloon
Apply manual pressure above and below IABP
Remove balloon while alternating pressure
above and below insertion site to expel clots
Apply constant pressure to the insertion site for a
minimum of 30 minutes
Check distal pulses frequently
The primary goal of intra-aortic balloon pump (IABP)
treatment is to increase myocardial oxygen supply and
decrease myocardial oxygen demand.
Decreased urine output after the insertion of IABP can
occur because of juxta-renal balloon positioning.
Haemolysis from mechanical damage to red blood cells
can reduce the haematocrit by up to 5%.
Suboptimal timing of inflation and deflation of the
balloon produces haemodynamic instability.
An IABP is thrombogenic; always anticoagulate the
Never switch the balloon off while in situ.