What is an Implantable Cardioverter Defibrillator (ICD)?
An ICD is a small device that monitors the electrical activity of the heart. This not only evaluates the hearts activity, but can also store the electrical events so Dr. Jamnadas can assess them.
In the event a dangerously fast heart rhythm is detected, the ICD quickly delivers therapy in the form of electrical energy.
This helps to regulate a normal heart rate and rhythm.
Who needs it?
- Ventricular Fibrillation
- Ventricular Tachycardia
- Congestive Heart Failure
- Long QT syndrome
How a normal heart beats:
In a normal heart, the muscles and chambers within the heart synchronize in a regulated type of harmony together. This occurs only when there is a normal rate and rhythm of the heart.
If the heart is beating too slow or too fast, sufficient amount of blood is unable to flow throughout the body. When this happens patients may get symptoms of arrhythmia. These symptoms include fatigue, shortness of breath, fainting, or loss of consciousness.
The electrical signals of the heart follow through a conduction pathway. The origin of this pathway is from the Sinoatrial node that is known as the natural pacemaker of the heart. The impulses are transmitted throughout the heart keeping it beating in sync in rate and rhythm.
What does an ICD do?
- Battery: the ICD battery supplies the power to the ICD. This is a small, sealed, lithium battery that can lasts for years. Battery life usually lasts 5-10 years depending on how active your ICD is.
- Computerized generator: this is a miniature computer to evaluate the heart rate, store it in memory, and help the device know when to deliver therapy. The battery transmits electrical impulses that go through this generator to stimulate the heart to beat.
- Case: the battery and computer generator are sealed inside a metal casing.
- Leads: are flexible wires connecting the generator to the walls of the heart.
What are the different types of ICDs?
- ICD with a single chamber pacemaker: this paces in one chamber of the heart. This uses one lead which connects either to the right atrium or ventricle.
- Dual chamber ICD with dual chamber pacemaker: this uses two leads with one connecting to the right atrium and the second connecting to the right ventricle to make the heart beat more efficiently.
- Bi ventricular ICDs: pace in three chambers of the heart including the right atrium and the left and right ventricles.
What are the risks?
- Allergy: may produce an allergic reaction to the dye.
- Swelling, bruising, or bleeding at or around the implantation site.
- Formation of a clot (hematoma).
- Infection: can occur where there ICD was implanted.
- Damage to blood vessels or nerves around ICD site.
- Collapse lung
How is this diagnosed?
- Electrocardiogram (EKG) – a simple,non-invasive test that records the electrical activity of the heart and its beating pattern.
- Holter monitor– records the electrical events of the heart during your normal daily activities. It is important to accurately record your activities and symptoms so Dr. Jamnadas can compare them to the Holter monitor findings. If symptoms do not occur within 24 hours, an event recorder may be ordered for you for up to 30 days.
- Echocardiogram (ECHO) – shows images of the heart determining the size and shape of the heart, and shows whether the heart walls and pumping activity are normal or performing weakly.
- Stress test– helps access the blood flow to the heart at rest and during stress. Will detect if any areas are receiving less blood flow.
What to expect: Before the procedure:
Today ICDs devices are amazingly small and average about 5 x 5cms, weighing only 1 to 3 ounces.
An ICD is usually implanted just beneath the skin of your chest, below the collarbone.
ICDs are typically placed on the left side of the chest, but this may not be suitable for everyone.
The procedure will take place within a hospital and does not require general anesthesia.
You may or may not stay over night in the hospital.
You will need to arrange for someone to pick you up and drop you off.
During the procedure:
The entire procedure usually takes about one to two hours.
A sedative will be given to help you relax through an i.v. in your hand or arm that may make you sleepy.
Under sterile precautions, Dr. Jamnadas will inject a local anesthetic until you are fully numb in the area where the ICD will be inserted.
A needle will be inserted into a large vein to get access to the heart.
A dye will be given to view the heart under x-ray guidance.
To enter the heart, the ICD leads will be threaded through the vein and fixed to the wall of the right atrium or ventricle or both, depending on your ICD. The other end of the lead will be secured to the generator box.
The ICD settings are programmed to help your heart beat at a rate that is right for you.
Once the leads are fixed, Dr. Jamnadas will place a single incision just below the collar bone to insert the ICD underneath the skin of the chest.
After the ICD is placed within the chest, it will be tested to make sure it is working properly.
The incision will then be closed and a dressing will be applied.
After the procedure:
- Change your dressing as often as instructed and avoid getting the area wet for about a week.
- Take your temperature and check the incision everyday for signs of infection like redness, discharge, or a local rise in temperature.
- Learn how to take your own pulse and keep record of it.
- Avoid putting direct pressure on your ICD. For example, do not lie on your chest while sleeping at night.
- Let your primary health care provider or any other healthcare providers as well as dentist know about your ICD before receiving any treatment.
- Carry an ID card that contains information about your ICD. Your ICD may set off a metal detector while going through security. You may need to show this card to security personnel.
- Keep your cellular phone away from your ICD. Do not carry your phone in your shirt pocket, even when it is turned off.
- Avoid strong magnets including MRI scans and hand held security wands.
- Avoid strong electrical fields such as those made by radio transmitting towers, ham radios, and heavy duty electrical equipment.
- Avoid leaning over the open hood of a running car. A running engine creates am electrical field.
What can I use?
- Microwave ovens
- Hair dryers
- Power tools
- Electric blankets
- Vacuum cleaners
- Heating pads
Call Dr. Jamnadas if you experience any symptoms of:
Shortness of breath
Twitching chest muscles
Chest pain or pain at ICD site
Hiccups that won’t stop