Total Artificial Heart
How Does It Work?
The TAH replaces the lower chambers of the heart, called . Tubes connect the TAH to a power source that is outside the body. The TAH then pumps blood through the heart’s major artery to the lungs and the rest of the body.
The TAH has four mechanical valves that work like the heart’s own valves to control blood flow. These valves connect the TAH to your heart’s upper chambers, called the , and to the major arteries, the pulmonary artery, and the aorta. Once the TAH is connected, it duplicates the action of a normal heart, providing mechanical circulatory support and restoring normal blood flow through the body. The TAH is powered and controlled by a bedside console for patients in the hospital. After they leave the hospital, people with a TAH use a portable control device that fits in a shoulder bag or backpack and weighs about 14 pounds. It can be recharged at home or in a car.
Normal Heart and a Total Artificial Heart Device
To understand how a TAH works, you may want to read how the heart works.
Who May Benefit?
You may benefit from a TAH if you have heart failure caused by ventricles that no longer pump blood well enough, and other treatments have not worked. If you are waiting for a heart transplant, a TAH can help prolong your life.
Talk to your doctor about whether you are eligible for a TAH and whether the benefits of the device outweigh the risks from surgery and possible complications from living with a TAH.
Who is eligible to get a TAH?
You may be eligible for a TAH if you have heart failure and both of your ventricles are working poorly. The Federal Drug Administration (FDA) approved the TAH device as a bridge to a transplant; TAHs help keep people with heart failure alive while they wait for a heart transplant. In addition, artificial hearts have been given to a few patients as part of clinical research. Researchers are working on smaller TAHs that will fit infants, children, women, and smaller men who are waiting for a heart transplant, as well as devices that are alternative treatments for adults who are not eligible for a transplant.
Who is not eligible to get a TAH?
A TAH should not be used if you have any of these characteristics or conditions:
- Are small. The device is too large to fit in the chests of children and some adults. Researchers are testing smaller TAHs in infants, children, women, and smaller men.
- Can benefit from other treatments, including medicines.
- Have heart failure on only one side of your heart. In these cases, treatment with a ventricular assist device may be more appropriate.
- Cannot take anticlotting medicines. These medicines are required as long as the TAH is in place.
If you are not already in the hospital, you will likely spend at least a week in the hospital to prepare for the TAH surgery. You will continue to take any heart medicines your doctor gave you. During this time, you will learn about the TAH that you are getting and how to live with it.
You and your loved ones will meet with your surgeons, your cardiologist, and other doctors and nurses who specialize in the heart. The members of your healthcare team will provide you with the information that you need before surgery, including steps you need to take at home to prepare. You can ask to see what the device looks like and how it will be attached inside your body.
Your doctors will make sure that your body is strong enough for the surgery. You may need to get extra nutrition through a feeding tube.
You may have the following tests before your surgery:
- Blood tests. Doctors use these tests to determine your blood type for any blood you may need during surgery and to check how well your liver and kidneys are working. The tests will also show your blood cell levels, as well as important chemicals in your blood.
- Chest computed tomography (CT) scan. This test takes pictures of the inside of your chest. Doctors use these pictures to make sure that the TAH, which is large, will fit in your chest.
- Chest MRI. This test creates detailed pictures of the organs in your chest, including your heart, lungs, and blood vessels.
- Chest x ray. This test also takes pictures of the inside of your chest. Doctors use these pictures to check your lungs, your heart, and your major arteries.
- Electrocardiogram. Doctors use this test to monitor your heart’s rhythm. It can show how well your ventricles are working before surgery.
- Echocardiogram. This test uses sound waves to create moving pictures of your heart. It shows the movement of the blood through your heart and major blood vessels to see, for example, whether there are any blockages.
- Pulmonary function tests. These tests measure how well your lungs work to help determine your risk for needing a ventilator for a long time after the surgery.
The surgery to connect the TAH is complex and can last from five to nine hours. Learn about the team that performs the surgery and the steps involved in connecting a TAH to your body.
As many as 15 people might be in the operating room during the surgery, including:
- Surgeons, who do the operation.
- Surgical nurses, who assist the surgeons.
- Anesthesiologists, who give you medicine that makes you sleep during the surgery.
- Perfusionists, who oversee the heart-lung bypass machine that keeps blood flowing through your body while the TAH is placed in your chest.
- Engineers, who assemble the TAH and make sure that it is working well.
Connecting the TAH device
An anesthesiologist will give you medicine to make you sleep before the surgery. During the surgery, the anesthesiologist will check your heart rate, blood pressure, oxygen levels, and breathing.
A breathing tube is placed in your windpipe through your mouth. This tube is connected to a ventilator machine that will support your breathing during the surgery.
Medicines are used to stop your heart. This allows the surgeons to operate on your heart while it is not moving. A heart-lung bypass machine keeps oxygen-rich blood moving through your body during the surgery.
To perform the surgery, your surgeons will cut into your chest bone to get to your heart. Your surgeons will open your ribcage, remove your heart’s ventricles, and attach the TAH to the upper chambers of your heart and to the aorta and the pulmonary artery. When everything is attached, the heart-lung bypass machine will be switched off and the surgical team will activate the TAH so it starts pumping. If the TAH is working properly and you are not bleeding abnormally, the surgeon will close your chest again. In some cases, it will remain partially closed for a few days. The medical team will fully close the chest once additional tests confirm that everything is working as it should.
Heart-Lung Bypass Machine
The image shows how a heart-lung bypass machine works during surgery.
Learn about recovery from surgery and possible surgery-related complications like blood clots or infection.
Recovery from surgery
Your hospital stay after surgery could last a month or more. Recovery time after TAH surgery will depend a lot on your health before the surgery.
Right after surgery, you will be moved to the hospital’s intensive care unit. You may still need a ventilator to help you breathe. For a while, you may receive fluids and nutrition through a feeding tube or an intravenous (IV) line in your arm. Your healthcare team will monitor another IV line in your neck or your leg to evaluate how the TAH is working. You will also have a tube inserted into your urinary tract to drain urine and to evaluate how your kidneys are working.
After a few days or more, you will be moved to a regular hospital room. Nurses who have experience with TAHs and similar devices will take care of you. The nurses will help you sit, get out of bed, and walk around. Most patients are able to get up and move around after two weeks. Nurses and physical therapists will help you gain your strength through a slow increase in activity.
Medical staff will perform exams such as blood tests as well as chest imaging tests, including CT scans, x rays, and echocardiograms (ECG or EKG). Since most of the heart has been removed, electrocardiograms, heart monitors, and procedures such as cardiopulmonary resuscitation will no longer be useful.
Once you become stronger, your healthcare team will remove your feeding, IV, and urine tubes. You will be able to begin eating regular food, go to the bathroom on your own, and take a shower. You will also learn how to care for your TAH at home.
During your recovery time in the hospital, you may enjoy visits from family or friends. These visitors can help you with various activities. They can also learn how to care for the TAH so that they can help you when you go home.
Read Living With for more information about living with and caring for your TAH.
Possible surgery-related complications
As with any surgery, there are possible surgery-related complications after getting a TAH such as blood clots, bleeding, or infection.
Blood may clot more easily as a result of the contact with the man-made parts of the TAH. Blood clots can block blood vessels that deliver oxygen to important organs in your body and can cause severe complications such as stroke; a type of venous thromboembolism called pulmonary embolism; or death. For this reason, you need to take anticlotting medicine as long as you have a TAH.
The surgery to connect a TAH to your heart is very complex. Bleeding can occur in your chest during and after the surgery. Anticlotting medicine also raises your risk of bleeding, because it thins your blood. Balancing the anticlotting medicine with the risk of bleeding can be hard. Be sure to take your medicine exactly as your doctor prescribes.
After surgery, you will be at risk for infection, so your doctor may prescribe medicine to reduce this risk. Your healthcare team will watch you closely for fever or other signs of infection. Other complications may develop:
The medical team will also watch you closely for the possibility of other complications including:
During the TAH surgery, there is a risk of dying. There is also a risk that your body may respond poorly to the medicine used to put you to sleep during the surgery.
Read Living With to learn more about possible complications of living with a TAH.
Learn about going home after TAH surgery, ongoing medical care you need, and possible complications of living with a TAH. If you are on the waiting list for a heart transplant, you will stay in close contact with the transplant center.
Slowly increase your activity level
Your recovery will continue after you go home. Once you are at home, you will need to slowly increase your activity level, protect and care for your TAH, and get the right nutrition and exercise.
When you go home after TAH surgery, you will likely be able to do more activities than you could before the surgery. The machine with the power supply and device controls is portable, so you will probably be able to get out of bed, get dressed, and move around the house. You may even be able to drive. Your healthcare team will advise you on the level of activity that is safe for you.
Protect and care for your TAH
Your healthcare team will explain how to troubleshoot your TAH, change or charge the portable device’s batteries, and respond to alarms.
A TAH is attached to a power source outside your body through holes in your abdomen. These holes increase the risk of bacteria getting in and causing an infection. Your doctor may tell you how often to check your temperature as part of your routine care. You may also need to take special steps before you bathe, shower, or swim. Your healthcare team will explain how to make sure that the tubes going through your skin do not get wet. They also will recommend that you avoid steam baths and dry saunas, which can overheat the TAH driver.
Get the right nutrition and physical activity
While you recover from TAH surgery, it is important that you get good nutrition. Talk with your healthcare team about following a proper eating plan for recovery. Read about heart-healthy eating.
Your healthcare team may recommend a supervised physical activity program. Physical activity can give your body the strength that it needs to recover. During the months or years before surgery when your heart was not working well, the muscles in your body may have weakened. Building up the muscles again will allow you to do more activities and feel less tired.
You will have regular checkups with your healthcare team to check your progress and make sure that your TAH is working well. There is a chance that you may have problems with your TAH. In some cases, you may need surgery again.
You will need to take anticlotting medicine to prevent dangerous blood clots as long as you have a TAH. Regular blood tests will help determine the correct dose.
You also will need to take medicine to try to prevent infections. Your doctor may tell you how often to check your temperature to make sure you do not have a fever, which can be a warning sign of infection.
Make sure to take all your medicines as prescribed and report any side effects to your doctor.
If you are on the waiting list for a heart transplant, you will likely be in close contact with the transplant center. Most donor hearts must be transplanted within four hours after removal from the donor.
You need to be prepared to arrive at the hospital within two hours of being notified about a donor heart.
Getting a TAH may cause fear, anxiety, and stress. If you are waiting for a heart transplant, you may worry that the TAH will not keep you alive long enough to get a new heart. You may feel overwhelmed or depressed.
These feelings are common for someone going through major heart surgery. Talk with your healthcare team about how you feel. Talking to a professional counselor also can help. If you are very depressed, your doctor may recommend medicines or other treatments that can improve your quality of life.
Support from family and friends can help relieve stress and anxiety. Let your loved ones know how you feel and what they can do to help you.
Problems with your device
There is a risk that the TAH will have problems and not work properly. For example, the device may not have the correct pumping action, the power source may fail, or parts may stop working well. Talk with your healthcare team about how to spot potential problems and what to do if a problem occurs.
If you have a TAH, you may want to download the product manual from the manufacturer site and visit Medical Device Recalls to learn about FDA recalls for these devices and their components.
We lead or sponsor studies relevant to total artificial heart. See if you or someone you know is eligible to participate in our .
Do you have a mechanical circulatory support device and would like to join a registry to help others?
After reading our Total Artificial Heart Health Topic, you may be interested in additional information found in the following resources.