HeartMate overview
Your doctor has recommended a Left Ventricular Assist System (LVAS) to help your heart. You know that your heart is weak, and is unable to pump enough blood to your body's organs and tissues. A system such as the HeartMate VE LVAS will aid your heart by pumping the blood your body needs. At the same time, the HeartMate can help stabilize your condition and allow you to become stronger until a donor heart can be found for you.
To help you and your family learn about the HeartMate VE LVAS, we have prepared this booklet. The information it contains will provide you with the basics of the LVAS therapy.
Why has the HeartMate been developed ?
Everyone needs more time. We all need more time to finish our work, more time with our families and friends, and more time to do things we enjoy.
Each year, thousands of people suffering from heart failure look for a way to gain more time. Cardiomyopathy, a disease which an enlarged or damaged heart is severely weakened, shortens the lives in spite of the finest medical therapy available. Their only hope for time is a heart transplant.
If you're one of the hundreds of people competing each year for a donor heart, time takes on a whole new meaning. There aren't enough donor hearts. Since the beginning, our goal at Thermo Cardiosystems has been to give desperately ill people more time - - more days, more months, more years - time that heart disease takes away from them.
The HeartMate LVAS was developed to take over the pumping function of the failing heart. More than 1,500 people around the world have benefitted from the gift of time because of the support of the HeartMate LVAS.
What is the HeartMate VE LVAS?
The HeartMate Vented Electric (VE) LVAS is a heart assist device specifically designed to take over the pumping function of the portion of the heart called the left ventricle. The HeartMate implantable system consists of an implantable blood pump, which contains an electric motor, and a driveline. The driveline connects to a small Controller and to 2 batteries which provide power to the pump. The system also includes a Power Base Unit for charging batteries and providing power while resting, and a Display Module that displays pump information.
The HeartMate blood pump....
The HeartMate blood pump itself is a flattened titanium cylinder about 2 inches thick and 4 inches in diameter. It weighs about 1200 grams (2.6 lbs).
The blood pump has 2 chambers: the blood chamber and the air/motor chamber. A flexible diaphragm (membrane) separates these 2 chambers. The membrane moves up and down when pushed by the motor.
The inside of the pump has special textured surfaces. One side is made of titanium, a very hard metal with tiny beads that create a highly textured surface, while the other is a textured polyurethane membrane. The textured surfaces help your body form a lining inside the device which mimics the inside of blood vessels. The helps prevents formation of blood clots inside the device. Because of this, an aspirin each day may be the only blood thinner you will need.
The HeartMate pump contains valves that act like one way doors, similar to heart valves. They allow the blood to flow in one direction, from the left ventricle through the pump and out to the body.
The HeartMate device is able to pump up to 10 liters per minute; that's more than 2 gallons of blood flow. The normal, healthy heart pumps 5 - 10 liters per minute.
How does it work ?
1. In a healthy heart, oxygen depleted blood enters the heart to be pumped to the lungs.
2. Blood flows through the right atrium, to the right ventricle; the heart muscle contracts and pumps the blood into the pulmonary artery which goes to the lungs.
3. Oxygen rich blood returns from the lungs.
4. Blood flows from the left atrium to the left ventricle and is pumped into the aorta to circulate throughout the body
5. When the HeartMate pump is implanted, it takes over the pumping function from the left ventricle.
Blood fills the HeartMate pump through a tube placed in the left ventricle. The diaprhagm of the pump moves up and down as the motor turns. This motion propels blood out of the pump into the aorta and the rest of the body. When the motor completes each revolution, the diaphragm moves down and blood from the left ventricle again fills the pump.
The rate of the pump varies depending on the operating mode selected on the small external Controller and on your activity. In the Fixed rate mode, the HeartMate system will pump at the same rate all the time. The Auto rate mode allows the HeartMate system to change pumping rate depending on your body's needs. The more you exercise, for instance, the more oxygen-carrying blood is demanded by the muscles. As a result, the device pumps faster. Yet, when you watch tv or sleep, less blood flow is needed and the pump rate slows. It is normal for the pump rate to be different from your heart rate.
Patients describe hearing or feeling the HeartMate pump working. For some, the sensation is that of their heart pounding. For others, the pump sounds like a heartbeat. The pump may seem loud at first, but most patients report becoming accustomed to it.
The HeartMate system controller....
Once your pump is implanted in you, it needs power to operate. The driveline coming through your skin provides the power by attaching to accessories. Accessories include the System Controller and batteries, or the Power Base Unit (PBU).
The System Controller acts as a manager for your pump. About the size of a deck of cards, the System Controller provides power to the pump from the batteries or the PBU, and it monitors the pump's operation. It tells the pump how fast to beat and whether it is in Fixed Rate or Auto Rate mode. The Controller also checks the pump at every beat to make sure it is working properly.
If any changes occur in the operation of your pump, the Controller will alert you with lights and sounds.
Rechargeable batteries
Most of the time, your HeartMate LVAS will be attached to two rechargeable batteries. The batteries are worn in holsters or a waist pack, so that you don't have to pull or carry anything. Fully charged batteries will last about 6 1/2 hours under normal conditions. Your System Controller will tell you when it's time to change your batteries.
The Power Base Unit
When you are plugged into the Power Base Unit, it provides continuous power for your LVAD. It is used at times when you are not active, such as when you are watching tv or sleeping. The PBU also acts as a battery recharger. It can charge and test up to 6 batteries at a time. It will tell you when the batteries are ready to use by lighting a green light.
The Display Module
Another accessory called the Display Module may be used in the hospital or at home. It connects to the PBU, and will display your pump's beat rate, stroke volume (how much blood is pumped with each beat) and the volume of blood flow each minute. It will also tell if you have an alarm condition. You must be connected to the PBU for the Display Module to work.
The surgical procedure to implant the HeartMate
If you and your medical team decide that you should receive the HeartMate LVAS, you will undergo open-heart surgery to place the device. You may be in the operating room for the surgical procedure for 4 to 8 hours.
Although each medical center has unique routines, many aspects of surgical preparation and of the surgery itself are similar. Things which happen prior to surgery include:
- x-rays and blood tests are performed.
- patients are not allowed to eat or drink anything after midnight prior to surgery.
- patients may be allowed tot take some or all of their medications with sips of water prior to surgery.
- an anesthesiologist will visit with the patient prior to surgery.
- the transplant nurse or LVAS Coordinator, who will be closely involved in their care following surgery, may visit patients.
Once you are under anesthesia, the surgeon makes a long incision from the top center of the chest down into the abdomen. Its length depends on your body size. A small incision is also made on the abdomen to allow the HeartMate driveline to exit the body. A heart-lung bypass machine does the work of your heart and lungs while the surgeon is implanting the HeartMate. The pump is placed in the left upper abdomen and tubes are placed to connect it to the left ventricle (from which it collects blood) and the aorta (to which it sends blood).
Once the HeartMate device is implanted, the tube exiting your abdomen is connected to the System Controller. After the HeartMate pump is functioning, the heart-lung bypass machine is removed, the incision is closed, and a bandage is applied to the incision and the drive line exit.
What to expect after the HeartMate surgery
The HeartMate system is intended to restore your circulation, enabling you to breath more easily and feel less fatigued. After surgery you can benefit from:
- improved circulation of oxygenated blood to your organs and tissues
- improved physical conditioning through participation in rehabilitation
After the surgery, you will recover in the surgical intensive care unit (ICU), an area specifically designed for patients who have undergone surgery. Here you will be carefully monitored while your body recovers from the immediate effects of anesthesia. When you awaken, you will notice many tubes and IV (intravenous) lines that were placed during surgery. These tubes are generally removed after the first few days after the surgery. Normally, after a short stay in the ICU, you will be moved into a regular hospital room.
You will probably feel some pain or discomfort at the incision sites following surgery. It is very important to let the nurses know that you are having pain so that they can give you pain medication.
REMEMBER: The longer you wait before requesting the medication, the less effective it will be. Without this pain medication, it may be more difficult to do the things asked of you such as coughing, deep breathing, sitting in a chair or walking. These actions are very important to your recovery.
Prevention of infection is also important for your recovery. You may be given antibiotics through an IV line for the first few days. After this, you may be given antibiotics only if an infection is suspected.
Your doctors and/or nurses will perform regular bandage changes at the incision and the drive line exit sites to help prevent infection.
Another key to successful recovery after HeartMate LVAS implantation is rehabilitation. You will be encouraged to get out of bed as soon as all tubes and lines are removed, usually within 3 days of surgery. At first, you will sit in a chair several times a day, and then you will begin to take short walks. Physical therapists and nurses will assist you in gaining mobility. Since the HeartMate VE LVAS is usually connected to batteries, you will be free to move around and take long walks. While on the HeartMate system, you may also use the treadmill, stationary bicycle, and other exercise equipment to help recondition your body prior to heart transplant or hospital discharge.
Nutrition also affects your recovery from surgery. The dietician may visit you to ensure that you are eating well. Some patients report a decreased appetite and a feeling of fullness after eating very little, due to the location of the pump near the stomach. During the initial days, frequent small meals throughout the day rather than a few large meals can relieve the fullness.
Living with your HeartMate LVAS
During your time on the HeartMate system, you will learn more about the device and participate in regular activities. You should walk in the hallways and in cardiac rehabilitation as often as your doctors and nurses recommend. You should eat regular, nutritious meals and drink plenty of fluids; learn all you can about your medications and take them regularly. Also, be aware of your own progress, and report changes to your medical team. Talk with your family and caregivers about how you are feeling emotionally and seek their support when you need it.
The portable design of the HeartMate VE LVAS means that you can be discharged from the hospital while supported by the pump. This will allow you to be at home with your friends and family instead of being confined to the hospital. Many patients feel well enough to return to work or school after leaving the hospital. Before being eligible for discharge, however, you will be thoroughly trained on the operation and care of your HeartMate system. Your medical team will continue your training until they are confident that you are ready to leave the hospital.
Best of all, as you feel better, you may experience the same improved quality of life that other HeartMate patients have reported.
Common questions about the HeartMate
1. How long can I be supported by a HeartMate pump?
Your doctor can use the HeartMate VE LVAS as long as necessary. Patients have been supported for nearly 2 years (updated : 3 years) on the HeartMate VE LVAS.
2. Will I be able to take a bath or shower while implanted with this pump?
You can safely take a shower once your doctor says it's okay and the nurses train you to protect your external equipment. Taking a bath is not allowed since you might get water inside your pump.
3. Is exercise possible while being supported by the HeartMate VE LVAS?
Yes. HeartMate VE patients have participated in many different activities including biking and ballroom dancing. While you are in the hospital, walking using the treadmill or the stationary bicycle will help to recondition your body prior to discharge from the hospital and heart transplant.
4. Will I need to take medications?
All patients have different medication needs after HeartMate device implantation. Patients often require fewer medications than before surgery. Your doctor will determine which medications you will need.
5. Do I need to follow a special diet?
Your doctor or nurse will recommend that initially you eat smaller portions more often and drink plenty of liquids. Once you are eating well and without discomfort, your doctor may allow you to return to a normal diet.
In Summary ........
The HeartMate VE LVAS can provide you with improved blood flow, better organ function, and the ability to become stronger before you leave the hospital.
For heart transplant candidates, it can provide you with the gift of time as you wait for that other special gift - a donor heart.