Cardiac Diagnostic Treatments
A defibrillator is a device that sends an electric shock through the heart muscle to restore a normal heartbeat. An implantable cardioverter defibrillator, or ICD, is a small device that is implanted under the skin in the upper chest and connected to the heart with wires called leads. Many who have survived a cardiac arrest and certain people with a high risk of developing arrhythmias called ventricular fibrillation or life-threatening ventricular tachycardia are generally considered candidates for ICD.
The implantable cardiac defibrillator is an electronic device placed in the body to help people who have life-threatening arrhythmias (heartbeat irregularities). The implantable defibrillator consists of a generator and a system of leads, or wires, which connects the generator to the heart. The generator is a smooth, lightweight metal case containing a tiny computer and a battery.
The titanium implantable defibrillator is smaller than a cigarette lighter and is placed under the collarbone. The wire lead runs through a vein and into the heart, and the device tracks the heart’s rhythm, activating when needed.
The implantable defibrillator can:
- Keep track of heart rhythms
- Send out electrical pulses and shocks when needed
- Record heart rhythm
- Record the pulses and shocks the defibrillation device sends out.
An implantable defibrillator can do one or more of the following to help a person’s heartbeat return to normal:
- Antitachycardia pacing
- Bradycardia pacing
To diagnose the cause of heart rhythm problems and to determine whether or not a person is a candidate for an implantable defibrillator, the physician may order one or more of the following tests:
- Electrocardiography (ECG)
- Cardiac catheterization
- Electrophysiology studies
The patient is instructed not to eat or drink for approximately 6 to 12 hours before the procedure. Patients who take daily medication should discuss with their physician whether or not the medication should be taken morning of the procedure. An implantable defibrillator is placed on the left side of a patient’s body in most instances.
What to Expect
During the procedure, the right or left side of the patient’s body is shaved and cleaned from the neck to the groin. Monitors are attached to the patient’s body and the patient is started on an intravenous line to provide fluids, medications, and an antibiotic. The patient is also connected to machines that monitor heart rate and electrical activity, to show the leads on an x-ray screen as they are guided into the heart, and, if necessary, help the patient breathe while he or she is under anesthesia.
When the procedure begins, the surgeon will make a small incision under the patient’s collarbone. A pocket-like space is made under the patient’s skin or muscle to hold the generator. The lead is placed into a vein and then guided to the patient’s heart. The lead tip attaches to the heart muscle, and the other end is attached to the generator. The generator is set to treat heart rhythm problems and then is placed under the skin.
The incision is then closed and covered with a sterile dressing. The procedure can take from 1 to 2 hours and is performed under conscious sedation.
Following the procedure, the patient will stay in the hospital overnight. The patient’s heart will be monitored to make sure the defibrillator is working properly.
Before leaving the hospital, the physician will schedule 15- to 20-minute follow-up appointments, which are very important and should occur every 2 to 4 months. Once home, the patient can usually resume most of his or her daily activities. The patient should avoid any strenuous activities for a couple of weeks. The patient should avoid raising that arm above his or her head on the side of the body where the device is implanted. Patients should check the incision area every daily signs of infection.
Patients should contact their physician immediately in the case of:
- Drainage around the site
- Fever over 100° F
- Tenderness, swelling, or redness at or around the incision
- Twitching chest muscles
- Increasing pain around the defibrillator
- Bleeding from the incision
- Swelling in the arm on the side of the incision site
Defibrillator implantation is a relatively simple, low-risk procedure.
However, complications can occur, such as:
- Infection at the incision site
- Nerve damage at the incision site
- Blood clots or air bubbles in a vein
- Tearing of a vein or artery wall
- Punctured heart or lung