A ventricular assist device (VAD) is a mechanical pump that helps the failing heart pump blood. Some VADs are short-term, while others provide long-term support. The most common type is the left ventricular assist device (LVAD) which helps the left ventricle. VADs carry risks like infection, blood clots, and device malfunctions but can help patients live longer while waiting for a heart transplant or serve as permanent heart failure treatment. After surgery, patients recover in the hospital while taking medications and regaining strength. Living with a VAD requires ongoing monitoring but allows many to return to normal activities with doctor approval.
2. A Ventricular assist device, or VAD, is
a mechanical circulatory device that is used to
partially or completely replace the function of a
failing heart. Some VADs are intended for short
term use, typically for patients recovering
from heart attacks or heart surgery, while
others are intended for long term use (months
to years and in some cases for life), typically for
patients suffering from congestive heart failure.
3. VADs need to be clearly distinguished
from artificial hearts, which are designed to
completely take over cardiac function and
generally require the removal of the patient's
heart.
VADs are designed to assist either the right
(RVAD) or left (LVAD)ventricle, or both at once
(BiVAD). Which of these types is used depends
primarily on the underlying heart disease and
the pulmonary arterial resistance that
determines the load on the right ventricle.
4. LVADs are most commonly used, but when
pulmonary arterial resistance is high, right
ventricular assistance becomes necessary. Long term
VADs are normally used to keep patients alive with a
good quality of life while they wait for a heart
transplantation (known as a "bridge to
transplantation"). However, LVADs are sometimes
used asdestination therapy and sometimes as a
bridge to recovery.
In the last few years, VADs have improved
significantly in terms of providing survival and
quality of life among recipients.
5. VADs are mechanical devices that support the
lower left heart chamber (left ventricular assist
devices, or LVADs), the lower right heart
chamber (right ventricular assist devices, or
RVADs) or both lower heart chambers
(biventricular assist devices, or BIVADs).
6. Your doctor may recommend you have a VAD
implanted if:
You're waiting for a heart transplant.
You may have a VAD implanted temporarily while
you wait for a donor heart to become available. A
VAD can keep blood pumping despite a diseased
heart and will be removed when your new heart is
implanted. When a VAD is implanted while you're
waiting for a heart transplant, it's referred to as a
"bridge to transplant."
7. Your heart's function can become normal again. If
your heart failure is temporary, your doctor may
recommend implanting a VAD until your heart is
healthy enough to pump blood on its own again. It's
also possible you'll have a VAD implanted for a short
time if you're recovering from heart surgery. You may
have a VAD implanted for only a few weeks or
months. RVADs are often temporarily implanted after
some heart surgeries. An RVAD can help keep blood
flowing from the right ventricle to your lungs.
8. You're not a good candidate for a heart
transplant. VADs are increasingly being used as a
long-term treatment for people who have heart
failure, but aren't good candidates for a heart
transplant. A VAD can improve your quality of life.
When a VAD is implanted as a permanent treatment
for heart failure, it's referred to as destination
therapy.
9. If VADs can't help your heart, another treatment
option your doctor may consider is a total artificial
heart (TAH). This device replaces the two ventricles
of your heart. Because a total artificial heart is
difficult to implant and can cause serious
complications, it's only used in a small number of
people.
11. The two basic types of VADs are a left ventricular
assist device (LVAD) and a right ventricular assist
device (RVAD). If both types are used at the same
time, they're called a biventricular assist device
(BIVAD).
12. The LVAD is the most common type of VAD. It helps
the left ventricle pump blood to the aorta. The aorta
is the main artery that carries oxygen-rich blood
from your heart to your body.
RVADs usually are used only for short-term support
of the right ventricle after LVAD surgery or
other heart surgery. An RVAD helps the right
ventricle pump blood to the pulmonary artery. This is
the artery that carries blood from the heart to the
lungs to pick up oxygen.
13. A BIVAD might be used if both ventricles don't work well
enough to meet the body's needs. Another treatment
option for this condition is a total artificial heart(TAH). A
TAH is a device that replaces the ventricles.
VADs have two basic designs. A transcutaneous VAD has
its pump and power source located outside of the body.
Tubes connect the pump to the heart through small holes
in the abdomen. This type of VAD might be used for
short-term support during or after surgery.
16. Before your VAD is implanted, it's likely you'll
stay in the hospital for some time preparing for
surgery. While you're in the hospital, you may
have other treatments for your weakened heart
or heart failure. Your doctors will make sure
you're healthy enough to have surgery to
implant a VAD. You may need many tests or
other procedures before the surgery, including:
17. Echocardiogram. An echocardiogram, which is an
imaging test, helps your doctor determine the
pumping function of your heart, check your heart
valves and help determine the cause of your heart
failure. This can help your doctor decide if you're a
candidate for a VAD and if there are any other
treatment options available.
Chest X-ray. Your doctor uses a chest X-ray to see
the size and shape of your heart and lungs.
18. Blood tests. Your doctor will order blood tests to see
if your liver and kidneys are working properly before
the surgery to implant your VAD. Your doctor might
also check for other chemicals in your blood that
show how well your heart is working. Blood tests are
commonly used to check for diabetes, thyroid
problems or symptoms of infection, which will need
to be treated before you can have surgery.
Electrocardiogram (EKG). An electrocardiogram
can help your doctor check your heart rhythm before
surgery.
19. Cardiac catheterization. In this test, a short tube
(sheath) is inserted into a vein or artery in your
upper leg (groin) or arm. A hollow, flexible and
longer tube (guide catheter) is then inserted into the
sheath. Aided by X-ray images on a monitor, your
doctor threads the guide catheter through that artery
until it reaches your heart. This test checks the
pressures in your heart and may be used to
determine if you are a candidate for a VAD and if you
may need additional devices.
21. The pumps used in VADs can be divided into two
main categories – pulsatile pumps, that mimic the
natural pulsing action of the heart, and continuous
flow pumps.
22. Continuous flow VADs normally use
either centrifugal pumps or an axial flow pump. Both
types have a central rotor containing permanent
magnets. Controlled electric currents running
through coils contained in the pump housing apply
forces to the magnets, which in turn cause the rotors
to spin. In the centrifugal pumps, the rotors are
shaped to accelerate the blood circumferentially and
thereby cause it to move toward the outer rim of the
pump, whereas in the axial flow pumps the rotors are
more or less cylindrical with blades that are helical,
causing the blood to be accelerated in the direction of
the rotor's axis.
24. Blood clots can slow or block normal blood flow
through your heart, which can lead to stroke or
heart attack, or cause your VAD to stop working.
Your doctor may prescribe a blood-thinning
medication such as aspirin or warfarin
(Coumadin, Jantoven) to help prevent blood clots
after your VAD is implanted. It's very important to
follow the instructions for taking warfarin
carefully to reduce the risk of life-threatening
blood clots. Warfarin is a medication that can
have dangerous side effects if not taken exactly as
instructed, so talk to your doctor about any
special instructions you'll need to follow.
25. Bleeding. Implanting a VAD requires open-heart
surgery. Having open-heart surgery can increase your
risk of bleeding after your operation. Taking blood-
thinning medications to reduce your risk of clotting
also increases your risk of dangerous bleeding into
the gastrointestinal track and the brain.
26. Infection. Because the power source and control unit
for your VAD are outside your body and connected
through a port in your skin, there's an increased risk
of germs getting in the port and causing a serious
infection. You and your medical team should watch
for signs of infection, such as soreness or redness
near the port, fluid draining from the site, or a fever.
27. Device malfunctions. It's possible that your VAD
may stop working properly after it's implanted. The
pumping action of the device might not work exactly
right, making it so not enough blood pumps through
your heart. The power supply to the device could also
fail, or other parts of the device may stop working
properly. Each of these problems requires immediate
medical attention.
28. Right heart failure. If you have an LVAD implanted,
it will pump more blood from the left ventricle of
your heart than what your heart might have been
used to. Your right ventricle may be too weak to
pump the increased amount of blood.
If you develop right heart failure, medications may
help improve the pumping ability of the right
ventricle. An RVAD might also be implanted to
support the right ventricle if you develop this
complication.
29. Treatment of VAD-related infection is exceedingly
difficult and many patients die of infection despite
optimal treatment. Initial treatment should be with
broad spectrum antibiotics, but every effort must be
made to obtain appropriate samples for culture. A
final decision regarding antibiotic therapy must be
based on the results of microbiogical cultures.
30. Other problems include immunosuppression,clotting
with resultant stroke, and bleeding secondary to
anticoagulation. Some of the
polyurethane components used in the devices cause
the deletion of a subset of immune cells when blood
comes in contact with them. This predisposes the
patient to fungal and some viral infections
necessitating appropriate prophylactic therapy
31. VADs extend the quantity of life. People
who have had VADs implanted have had
lower rates of depression than those
people suffering from cardiac disease
that have not undergone implantation
surgery.
33. During the procedure
The procedure to implant a VAD is an open-heart
surgery that usually takes four to six hours. You'll be
asleep during the procedure, so you shouldn't feel
any pain during the procedure.
You'll be connected to a machine that helps you
breathe (ventilator) during your surgery. A tube will
be run down your throat to your lungs and connected
to the ventilator. You may need to remain connected
to the ventilator for several days after your surgery.
34. A cut will be made down the center of your chest.
Your chest bone (sternum) is separated and your rib
cage is opened so that your doctors can operate on
your heart. Your heart is stopped during the surgery.
You will be connected to a heart-lung bypass machine
that keeps oxygenated blood flowing through your
body during surgery.
Once your VAD is implanted and working properly,
your doctors will take you off the heart-lung bypass
machine so that the VAD can begin pumping blood
through your heart.
35. Some VADs pump blood similar to the way your heart
does, with a pumping action. Other VADs allow a
continuous stream of blood to flow through your
heart. If you have a continuous stream of blood
flowing through your LVAD, you may not have a
normal pulse, even though your body is getting the
blood it needs.
37. When you wake up from your surgery, you'll be in the
intensive care unit (ICU). You'll stay in the ICU for
several days, where you'll be fed and given fluids and
medications through an intravenous (IV) line. You'll
have a tube in your bladder to drain your urine and
other tubes in your chest to drain fluid and blood.
Your lungs may not work properly immediately after
your surgery, so you may need to remain connected
to a ventilator for a few more days until you're able to
breathe on your own.
38. After a few days in the ICU, you'll likely be moved to a
regular hospital room. As you recover, nurses will
help you become increasingly active. They may help
you get out of bed, sit up and walk around the
hallways of the hospital. You may also have visits
with a physical therapist to help you continue to gain
strength and get used to performing daily activities.
The amount of time you'll spend in the ICU and in the
hospital can vary, depending on your condition
before the procedure and how well you recover after
your VAD is placed.
39. You'll likely be prescribed antibiotics and blood-
thinning medications to prevent infection and other
complications while you're in the hospital. Your
doctor will order blood tests periodically to check
your kidney function and to make sure your
medications are effective.
While you're recovering in the hospital, it can be
helpful to have friends and family visit. Visitors can
help you perform some physical activities, and they
can learn to help you care for your VAD when you go
home.
41. After you're released from the hospital, you may be
able to return to most of your daily activities.
Depending on your condition, you may be able to
return to work, be sexually active and drive. Your
doctor should tell you what activities are appropriate
for you.
42. You will likely have weekly appointments at a
specialized clinic or hospital to check how well your
VAD is working. Your doctor may also recommend a
cardiac rehabilitation program (cardiac rehab).
Cardiac rehab is a customized program of exercise
and education, designed to help you recover after a
heart attack, from other forms of heart disease or
after surgery to treat heart disease.
43. Living with a VAD can seem stressful. You may worry
that your VAD will stop working or that you'll get an
infection. If you're waiting for a heart transplant, you
may worry that your VAD won't keep you alive long
enough to receive a donor heart. Tell your medical
team and family if you feel this way. It may help to
discuss how you're feeling, join a support group or
talk with a professional counselor.
44. VADs and heart transplants
If you have a VAD implanted to help your heart pump
blood while you wait for a heart transplant, you'll
remain in close contact with your doctor and
transplant center while you remain on the waiting
list. It's likely you won't be allowed to travel farther
than two hours driving time of your hospital in case a
donor heart becomes available.
45. ALTERNATIVE TREATMENTS
Your doctor will initially attempt to treat your heart
disease with medications and lifestyle .
Medications often used to treat heart failure
include beta blockers and ACE inhibitors, which decrease
the workload of the heart. Diuretics are often used to get
rid of excess fluid which accumulates as a result of heart
failure. Examples of good lifestyle changes that can make
the heart healthier are:
.• Regular exercise and weight loss
• Cholesterol and blood pressure management with they
help of your doctor
• Smoking cessation
• Controlling diabetes (if applicable)