An intraaortic balloon pump (IABP) is a device that increases blood flow to the heart muscle and decreases the heart’s workload through a process called counterpulsation. It can produce up to 20 percent of the heart’s workload.
The IABP is placed in the aorta, which is the main artery that carries oxygen-rich blood to the rest of the body.
Most commonly inserted on a long, thin tube called a catheter, IABPs are regularly used to treat angina, wean patients off the heart-lung machine during open-heart surgery, assist in complicated balloon angioplasty procedures and various other cardiac situations.
This assistance from the IABP can also be life-saving for a patient with severe heart disease or damage, such as following a massive heart attack or while waiting for a heart transplant. With more than 70,000 IABP procedures performed every year, it is the most common circulatory assist device in the United States.
Although the risk of complications from an IABP has dropped in the past 40 years, it still carries some risks to the patient. People are encouraged to speak with their physician about the benefits and risks of this device.
About intraaortic balloon pump (IABP)
An intraaortic balloon pump (IABP) is a device that increases blood flow to the heart muscle and decreases the heart’s workload through a process called counterpulsation.
In the early 1950s, researchers discovered that the heart is doing two different kinds of work. The first type of work occurs during the pumping part of the heartbeat (the systole), during which the heart must overcome the blood pressure in the aorta in order to pump blood through it. The second type of work occurs during the relaxed part of the heartbeat (the diastole), during which the heart receives blood via backflow from the aorta. This is described as the difference between pressure work and flow work, respectively. The flow of blood to the heart muscle through the coronary arteries mainly occurs during the diastole. A healthy heart is normally able to accomplish both types of work effectively, but a weakened heart will have more difficulty.
Counterpulsation was introduced as a strategy by which the blood flow to the heart muscle could be increased during diastole (less flow work). The increased blood flow provides the heart with more oxygen, which improves circulation, cardiac output and the heart rate. As a result, the technique relieves, for example, the pain and discomfort from angina.
The IABP device contains a small balloon that is inflated inside the aorta when the heart muscle relaxed, increasing pressure inside the heart chambers and increasing blood flow to the coronary arteries. Then the balloon is deflated just before the heart muscle pumps, creating a vacuum effect that aids blood flow from the heart, thus reducing systolic blood pressure and increasing the heart’s ability to pump blood. In this way, the device improves blood flow to the heart muscle and reduces the workload of the heart muscle.
The IABP has been modified and improved upon numerous times since its introduction in 1967, including its adaptation to catheters. Today, IABPs are inserted using catheters. The gas used to inflate the balloon is either carbon dioxide (which has fewer consequences in the rare event of a balloon bursting) or helium (which has the fastest ability to travel or diffuse).
With more than 70,000 IABP procedures performed every year, it is the most commonly used circulatory assist device in the United States. For instance, the IABP is used to help wean high-risk patients off the heart-lung machine after bypass surgery. It also is used in the early support and stabilization of high-risk patients undergoing angiography and angioplasty.
Other uses include:
Treating patients with shock due to left ventricular failure or heart attack
Treatment of intractable angina
Among patients with severe coronary artery disease who are waiting for surgery
Because it is placed in the aorta, patients with aorta-related problems (e.g., aortic dissection, aortic regurgitation) are not generally eligible for this treatment.
About IABP insertion
The most common strategy for inserting an intraaortic balloon pump (IABP) is a catheter-based procedure. This procedure is done in the operating room, a catheterization laboratory or a hospital’s intensive care unit (ICU). In an emergency, it may be performed in the patient’s hospital room before the patient is moved to the ICU.
Just prior to the procedure, the area to receive the catheter is shaved (if necessary) and sterilized to prevent infection, and a mild sedative may be given to calm the patient. Once the patient is made comfortable, heart monitoring begins, an intravenous (I.V.) line is inserted and the area to receive the catheter is numbed with local anesthesia. The injection of the local anesthesia may result in a brief period of discomfort. This is normal and should be no cause for concern.
Once the local anesthesia takes effect, the physician will prepare to insert an IABP-tipped catheter. The IABP-tipped catheter is usually inserted through the femoral artery in the groin and guided all the way up to the aorta. Once inserted in the aorta, the catheter remains there until the IABP is removed.
The IABP is connected through the catheter to a computer console at the base of the patient’s bed, and patients will often feel its rhythmic pulsing as it controls the inflation and deflation of the IABP. The console includes a number of electrical devices, including:
Controls for adjusting the IABP’s inflation and deflation
Emergency backup power supply
Monitor for recording electrocardiogram (EKG) and pressure wave data
If the catheter is inserted through the femoral artery in the groin, patients are usually asked to keep that leg straight. A critical care team monitors the patient’s progress and should be notified immediately if the patient feels any sudden discomfort or wetness where the catheter was inserted.
Benefits and risks with IABP
The IABP offers the following potential benefits:
Improved circulation
Lower heart rate and decreased workload of the heart
Improved efficiency of the heart’s pumping
Increased supply of oxygen to heart tissues and decreased demand for it
Less pressure resistance in the aorta when the heart pumps (during the systole)
More pressure in the aorta when the heart is relaxing, thus increasing blood flow to the heart muscle (during the diastole)
The risk of complications has dropped as the IABP has evolved over the last 40 years. However, there are some complications that are still reported in some patients, which include:
Damage to the aorta or femoral artery
Heavy bleeding (hemorrhaging), occasionally from the site of insertion
Infection
Lack of oxygen-rich blood to either a limb (limb ischemia) or an organ (visceral ischemia), due to narrowed blood vessels
Tearing or bursting of the balloon, releasing gas into the bloodstream with potentially dangerous results
In addition, not all patients are suited for IABP. Patients who may not be recommended for IABP use include:
Those with conditions of the aorta, including aortic regurgitation, abdominal aortic aneurysm or aortic dissection
Those with uncontrolled bleeding
Those with severe peripheral vascular disease
Variants and alternatives to IABPs
Another early variation of aortic counterpulsation used cuffs that were wrapped around the lower legs and timed to alternately empty and fill with water in the same rhythm as the patient’s heartbeat. Today, the technique of enhanced external counterpulsation (EECP) uses cuffs filled with air instead of water. This is more comfortable for the patient and easier for the physician. The cuffs fill sequentially, filling with air all around the lower leg, rather than suddenly filling all at once.
In 1989, researchers determined that enhanced external counterpulsation continued to show helpful effects on patients even three years after treatment. Patients with angina report a decrease in episodes of chest pain, decrease in angina medication, and increase in stamina during exercise.
There are no reported risks of complication. However, EECP is not recommended in patients with certain factors, including:
Uncontrolled arrhythmia
Uncontrolled heart failureheart failure
Bleeding or clotting problems
Blood pressure higher than 180/110
Moreover, EECP is a scheduled, non-emergency procedure rather than an emergency procedure, for which an intraaortic balloon pump (IABP) may still prove to be more effective.
Longevity of IABP use
The intraaortic balloon pump (IABP) usually remains implanted for a short period of time, such as in the following situations:
Before, during or after open-heart surgery or balloon angioplasty (in high-risk patients)
During acute attacks of angina
In emergency situations (e.g., heart attack, heart failure, very low blood pressure due to cardiogenic shock)
Throughout waiting periods as patients prepare for either a heart transplant or a mechanical heart
In most cases, an IABP is needed for a few days. Sometimes it is used for a week, and in rare cases for a full month.
Questions for your doctor
Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions about the intraaortic balloon pump (IABP):
Could an IABP be used to treat someone with my condition?
Would you recommend this treatment option?
Are there any risks associated with the IABP? How invasive is the placement of the IABP?
Are there any alternatives to the IABP available to me?
Could the IABP help me get off of a heart-lung machine? How long would it take?
Would the IABP procedure be performed along with any other procedures?
How effective do you expect the IABP to be for someone in my condition?
How long will it take me to recover from a procedure that places the IABP?
Will I need to limit my physical activities after the IABP is placed?
Does my medical condition permit me to undergo IABP treatment?
