Technology & Procedures
Implantable Cardioverter Defibrillator (ICD)
The Implantable Cardioverter Defibrillator (ICD) is a device placed
in your body to help control your heart rhythm (the speed and pattern
of your heartbeat). This rhythm is set by signals from the heart's
electrical system. A problem with these signals can cause your heart
to beat too quickly, too slowly, or irregularly. This is called
symptoms of a fast heart rhythm may include:
(a fluttering, fast heartbeat) Dizziness or Lightheadedness
rhythm problem can stop the heart from pumping blood. This is called
cardiac arrest and can be life threatening. (Note: Cardiac Arrest
is not the same as a heart attack. A heart attack is when a blood
vessel to the heart muscle is blocked.)
may be given an ICD if you have had a cardiac arrest or if you have
a fast heart rhythm problem that could lead to cardiac arrest. The
ICD is not a cure for your heart rhythm problem. It can save your
life by quickly bringing a dangerously fast heart rhythm under control.
You will need an ICD for the rest of your life, so having one implanted
means a lifelong commitment.
with electrical signals can cause very fast heart rhythms. Two common
types of heart rhythms are Ventricular Tachycardia (V-Tach) and
Ventricular Fibrillation (V-Fib). Both can lead to cardiac arrest,
so an ICD is usually needed.
ventricular tachycardia, a ventricle contains a group of abnormal
electrical cells called a circuit. The circuit sometimes sends out
signals that make the lower chambers beat very fast. The chamber
don't have time to fill with blood before the next beat. So, the
heart pumps less blood than the body needs, causing your symptoms.
V-Tach can progress to a more serious arrhythmia, V-Fib.
ventricular fibrillation, abnormal circuits in the ventricles sometimes
send signals quickly and irregularly. The heartbeat can be so fast
and uneven that the heart muscle quivers rather than pumps. A quivering
heart is in cardiac arrest. Emergency treatment must be given to
get the heart pumping again, or death may result.
and V-Fib usually develop in damaged heart muscle. This damage may
be caused by:
scar on the heart muscle from a heart attack
which is a diseased, weakened heart muscle
problems, including heart valve problems and congenital (present
at birth) heart problems
a heart rhythm problem can exist even though the heart muscle hasn't
been damaged. This is called a primary electrical problem. An Implantable
Cardioverter Defibrillator (ICD) can help.
ICD is a small, lightweight electronic device that is place inside
your body. It keeps track of your heart rhythm. When you have an
arrhythmia, the ICD helps your heart return to its normal rhythm.
An ICD can do one or more of the following:
- Antitachycardia pacing (ATP): The ICD can send
out a series of pulses to override a fast rhythm. This may feel
like fluttering in your chest, or may not be felt at all.
- Cardioversion: If ATP doesn't slow a fast rhythm,
the ICD can give the heart one ore more small shocks. These break
up the fast rhythm. They may feel like thumps in your chest.
- Defibrillation: If the ICD senses a very fast,
irregular rhythm, it quickly sends a strong shock to the heart
to override the fast rhythm. You may feel this as a strong kick
in your chest.
- Bradycardia Pacing: An ICD's main job is to slow
a fast heart rhythm. At rare times, your heart may beat to slowly.This
may happen if you have a second heart rhythm problem that causes
a slow heartbeat. Your heart may also beat too slowly after an
ICD shock. Most ICDs can send out pulses to get a slow heartbeat
back to the right speed.
the ICD into your body is called implantation. ICD implantation
is not open heart surgery. Rather, it's a minor procedure that's
done in an operating room or cardiac catheterization lab. You'll
be given instructions on how to prepare for the procedure. The ICD
can be inserted near the right or left shoulder. If you prefer to
have it implanted on a particular side, discuss your preference
with your doctor.
your doctor whether you should stop taking aspirin or other medications
before your procedure. Unless instructed otherwise, don't eat or
drink anything for six hours before the procedure. Before the procedure
begins, you may be given some medication to help you relax. This
medication will help you "sleep" through part or all of
the procedure, so you won't feel pain. The skin where the pacemaker
is to be implanted will be washed and shaved.
incision is made in your skin below your collarbone. For an abdominal
implant, a second incision is also made below your ribcage. A small
"pocket" (space) is made under your skin or muscle for
the ICD generator to sit in. For the abdominal implant, the pocket
is made near the incision below the rib cage.
lead for the ICD is threaded through the incision into a vein in
your upper chest. The
lead is then guided into your heart's chambers using x-ray monitors.
Electrical measurements are taken to determine a good position for
the lead in the heart. For an abdominal implant, the other end of
the lead is threaded under the skin from the chest to the abdomen.
ICD generator is attached to the lead. Then, the generator is placed
in the pocket under your skin. The ICD's settings are programmed
to treat your heart rhythm problem. The incision is then closed
and covered with a sterile dressing.
A patch electrode is sometimes also used to help the ICD do its
job. If one is needed, your doctor will make another incision to
place the patch under the skin or muscle near your heart. A lead
connects the patch to the generator.)
rare cases, the ICD may be implanted through open chest surgery.
this may be done along with open chest surgery for another heart
problem, or if problems keep the leads from being placed in the
veins. The chest is opened and the leads are attached to the outside
of the heart. The generator is placed in a pocket in the abdomen.
your ICD is implanted, you'll probably stay in the hospital for
a day or two. Before you go home, you will be told how to take care
of your incision site or sites as they heal. You may have some tests.
You'll also have some follow-up visits scheduled.
your stay in the hospital, your heart's signals are monitored to
be sure the ICD is working right. A nurse may take your pulse and
blood pressure and check your incision for bleeding or swelling.
Before you go home, an x-ray of your chest may be taken. The ICD
settings may also be rechecked. This is done from outside your body.
For a week or so, it's normal to have some pain and stiffness around
your incision. Pain medication can help make you more comfortable.
Don't raise the arm on the side of the incision above your shoulder.
This will give the lead a chance to secure inside the vein and your
heart. Be sure to tell your nurse if you feel any unusual symptoms
like hiccups that won't go away, dizziness, chest pain or shortness
home, you can go back to most of your daily activities. But take
it easy for a month or so to avoid pulling the lead or leads out
of place. For a few weeks, you may feel numbness or fullness in
the area around the ICD. This is normal.
the doctor, usually in a week or so. During this visit, the doctor
may remove your sutures or staples, if you have them.
raising the arm on the side of the ICD over your head. Your doctor
will tell you for how long - usually 2 to 6 weeks.
your doctor when you can return to activities like heavy lifting,
running, or contact sports.
incision should heal completely within about a month after the implantation.
You may feel and see a small bump under your skin where the ICD
is. This won't be noticeable under your clothes. Even after you
heal, avoid playing with the ICD under your skin. If you take medications
for your heart problem, keep taking them as directed. Talk to your
doctor about driving. In some cases, driving may be restricted.
This would be due to your heart rhythm problem, not the ICD.
your doctor if you notice any of the following:
of an infection (a fever over 100 degrees F; redness, swelling
or warmth at the incision site; drainage from the incision)
pain around your ICD
from your incision
arm on the side of the incision site
be sure your ICD is working right, you'll need to visit your doctor
or clinic several times a year. During these visits, the ICD's record
is checked and the ICD's settings can be changed, if necessary.
The settings can be changed from outside your body, without the
need for surgery. You may still feel symptoms when you have a fast
heart rhythm, but your ICD will stop them. If you do feel symptoms,
follow your doctor's advice on what to do next. Tests such as an
ECG may be performed. Your ICD's battery will also be checked. ICD
batteries last 3 to 7 years. Your doctor will know well in advance
when the battery needs to be replaced. The battery won't run down
you have an event, you may feel your usual symptoms of a fast heart
rhythm. If you do, find a place to sit or lie down. Put your feet
up. If possible have someone stay with you for about 15 minutes.
You won't always feel the ICD working. Low-energy pulses may be
enough to slow your heart rhythm. If a shock is needed, though,
you will feel it. It may feel as light as a thump or as strong as
a kick to the chest. Whether you feel it working or not, you can
rely on your ICD to treat you when you need it. Very rarely, a person
with an ICD may need additional medical care. Know what to do if
you have an event and feel okay afterward, let your doctor or nurse
know. (This is not an emergency, so call during business hours.)
to Call 911 (Emergency)
still feel symptoms after a shock
feel 3 or more shocks in a row
symptoms don't away and you feel no shock
[Note: If you have a very fast, irregular
heart rhythm, your blood pressure will drop sharply and you may
pass out. Your ICD will soon slow the heart rhythm and you'll wake
up. A friend or family member should call 911 (emergency) if you
stay unconscious for more than 30 seconds.]
ICD won't keep you from living an active life. You can usually do
almost everything you did before you got your ICD, and since you
will probably feel better, you may do even more!
you first get your ICD, you'll be given an ID card to carry. This
ID card contains important information about your ICD. It also tells
others what to do in an emergency. Show it to any doctor, dentist,
or other medical professional you visit. Also, because pacemaker
tend to set off security devices like those found in airports and
libraries, you may need to show your card to security personnel.
Hand-held security wands (such as those in airports) may affect
your ICD. Show your card to avoid this type of scan. You should
get an ID bracelet or necklace saying you have a heart rhythm problem
and an ICD. Ask your doctor or nurse for your rate cutoff - the
heart rate at which your ICD begins treatment. Other healthcare
providers may ask you for this number.
are well protected from outside signals, so there are very few things
that can interfere with your pacemaker. But if you ever feel symptoms
that make you think a device is disrupting your ICD's signals, turn
the device off or move away from it. Your symptoms should stop and
your ICD shouldn't be damaged. To be safe, check with your doctor.
which should be safe to use include:
ovens and other appliances in good repair
Blankets and Heating Pads
are a few things to avoid that might interfere with your ICD. These
include very strong magnets (like those used for an MRI or in hand-held
security wands), radio transmitting tours, ham radios, certain surgical
instruments and cellular phones. When using a cellular phone, hold
it on the ear farthest away from your pacemaker. Don't carry it
in your breast pocket, even when it's turned off. Also, a running
car engine generates an electrical field, so avoid leaning directly
over the open hood of a running car.
an ICD, you'll know that your heart rhythm problem can be managed.
Now you can live your life to the fullest. Talk to your doctor about
exercise and ask whether there are any activities you should avoid.
Take care of yourself and see your doctor regularly to ensure that
you stay healthy and feeling good!