Ventricular assist devices are mechanical pumps used in the treatment of weakened hearts, such as those affected by heart disease. These pumps push blood throughout the body when the heart cannot on its own. There are two main types of VADs:
- Left Ventricular Assist Device (LVADs)
- Right Ventricular Assist Device (RVADs)
What is a Left Ventricular Assist Device?
A left ventricular assist device (LVAD) is the most commonly implanted VAD and is used to help the left ventricle of the heart supply blood to the aorta.
The aorta is the primary artery which carries oxygenated blood from the heart to the body. When the heart can no longer pump blood through the aorta, a left ventricular assist device is implanted.
How an LVAD Works
Open-heart surgery is required for implantation of a left ventricular assist device. During that surgery, an incision in the patient's chest allows doctors to place the LVAD inside the recipient's abdomen.
From the LVAD, one tube is then routed to the left ventricle and another tube to the aorta. The pump is then confirmed functional with blood flowing freely through the aorta.
Once the pump, heart, and aorta are working together well, the incision is closed and the patient is sent to recovery.
Although an LVAD is implanted, there are functioning parts connected to the apparatus outside of the patient's body.
Inside the body are the pump and heart-to-aorta connections. Outside are a battery pack and external control unit. The external controls are connected to the pump through a small hole in the patient's abdomen. The patient then can wear the battery pack like a holster, on shoulders and around the waist.
Candidates for a Left Ventricular Assist Device
Until recently, an LVAD was primarily for patients with end-stage heart problems who were awaiting transplant.
Patients of today can utilize these life-saving implants in earlier stages of heart failure.
Those who are not eligible for a heart transplant can also receive a left ventricular assist device as what is called "destination therapy." This means they will wear the device to sustain their life and keep the heart operational until death. Regardless of the expected outcome, implanted LVADs provide quality of life and time for those awaiting a donor heart.
People with other long-term health issues may not be eligible to get a left ventricular assist device. Such prohibitive issues include acute kidney failure, brain trauma, serious infections and other health problems.
At one time only men were able to get LVADs due to how large they were. Women and children are now able to get LVADs because of design advances in LVADs. However, very small children and infants cannot yet wear a left ventricular assist device. The smallest and lightest LVAD in the world is the HeartAssist5® and can accommodate children as young as four years old1.
Left ventricular assist device implantation carries some serious risk. Blood clots, infection, device malfunction and heart failure are all common concerns.
Blood clots, which add the risk of stroke and heart attack, commonly occur around the VAD itself. Anti-clotting medications such as Warfarin will be prescribed by the LVAD patient's doctor. These post-surgical prescriptions are critical and will help the patient reduce the risk of dangerous clots.
Infection is always a big concern as part of any surgical procedure. For LVAD patients, infection can occur in surgery, after the operation, and through ongoing use of the LVAD. This is because there is an open incision in the patient's abdomen where the LVAD device is connected to a battery supply. The open incision remains as long as the device is connected. This can be a gateway for bacteria. It is imperative that the patient follows guidelines of care and keeps their doctor aware of any physical signs of infection.
Device malfunction is also common problem. Since LVAD's contain moving parts and are supported via a power source, it is possible the device could fail or malfunction. Newer generation pumps such as the HeartAssist5® provide remote monitoring of the device and will alert the VAD coordinator of any issues with the device.
Another concern is heart failure, the left side of the heart is better supported by the device and the right side will operate on its own. This brings risk of right heart failure if the right ventricle is not strong enough to support the flow of blood.
Although an LVAD poses a lot of risk, it is often the last option for someone going through heart failure and for those ineligible for a heart transplant and can help extend a persons life.
Citations (view all)
- 1. ReliantHeart, "Smallest Size and Weight" Accessed January 17, 2015. http://reliantheart.com/heartassist5/new-heart-assist-5/smallest-size-and-weight/.