Cardiac Defibrillator Implantation
What is it?
An implantable cardiac defibrillator (also known as a defibrillator, implantable cardioverter defibrillator, ICD or cardiac implantable device) is an electronic device that attaches to the heart and monitors your heart rhythm. If it detects a dangerous arrhythmia, it will deliver electrical impulses to your heart to shock it back to a normal rhythm. An ICD helps prevent sudden death in people at risk for dangerous heart rhythms.
You may need an ICD if you have had prior episodes of ventricular tachycardia, ventricular fibrillation or cardiac arrest. You may also benefit from an ICD implantation if you have a history of coronary artery disease, have had a heart attack that led to a weakened heart, or some kinds of heart conditions or heart defects.
An ICD consists of a small device called a pulse generator and one or more leads (wires) that connect the heart to the pulse generator. The pulse generator contains a battery and a tiny computer. The computer receives information about your heart rate from the leads attached to your heart. The leads pick up electrical activity in the heart and send information about your heart rate to the computer. The computer is programmed to know the difference between a normal rhythm and abnormal rhythms, so if your heart begins to beat abnormally, the computer tells the battery to deliver energy to the heart. That energy flows through the leads to your heart and shocks your heart back to a normal rhythm.
The ICD’s computer can be programmed to deliver different types of electrical impulses (therapies), depending on the type of heart rhythm irregularity you’re experiencing. The therapies can attempt to gently pace you out of a fast rhythm, act as a pacemaker if the heart beats too slowly, or deliver a shock in the event you experience a dangerous heart rhythm.
There are three general types of therapies that can be delivered via an ICD:
Low-energy pacing therapy is a series of slight electrical impulses to restore a normal heart rhythm when the heart is beating too fast (tachycardia) or too slow (bradycardia). There are two forms of low-energy pacing therapy: Anti-tachycardia pacing (ATP) therapy and bradycardia pacing therapy. You may feel nothing, or you might feel a painless fluttering in your chest as your ICD delivers this therapy.
Cardioversion therapy is a higher-energy shock delivered at the same time as your heartbeat to help restore a normal rhythm when you’re experiencing more serious rhythm problems. When therapy is delivered, you might feel as if you’ve been thumped in the chest.
Defibrillation therapy is a fast, high-energy shock delivered to the heart to restore a normal rhythm when the heart is beating dangerously fast, is quivering or isn’t beating at all. If your ICD delivers defibrillation therapy, you might feel like you’re being kicked in the chest. It could even knock you off your feet. But the pain typically lasts no more than a second. Most likely, you will only need one shock to restore a normal heartbeat, but sometimes, your ICD may deliver two or more shocks in a 24-hour period.
An ICD can also be combined with a pacemaker if two devices are necessary to provide adequate therapy.
The ICD is implanted under a local anesthetic. Your surgeon will make small incisions in your chest where the leads will be inserted. Using a fluoroscope, your surgeon will attach the tips of the leads to the heart muscle, and the other end of the leads will be attached to the pulse generator. Finally, the pulse generator will be placed in a pocket that has been created under your skin. After the leads are in place, your surgeon will "pace" them, a test to make sure they are placed correctly and functioning properly.
You must have your ICD device monitored several times each year in an ICD clinic that has the equipment to communicate with the device. During your appointment at the clinic, a nurse will use a programmer to retrieve reports of any therapies that the ICD delivered and to make any necessary adjustments to the device. He or she will also check the battery status to make sure your ICD battery is working and is prepared to deliver therapy if necessary. ICD batteries usually last five to eight years.
Remember, ICD implantation is only part of your overall treatment program. Although an ICD can help prevent serious arrhythmias and cardiac arrest, it can’t prevent or cure heart disease. It’s still important for you to take care of yourself by taking prescribed medications, going to your follow-up appointments, eating a balanced diet and maintaining a healthy lifestyle. You are an important part of your health-care treatment team, and your actions and attitude can go a long way toward improving your quality of life.
The Loyola difference
Loyola's team of expert electrophysiologists, advanced practice nurses, pacemaker clinic nursing staff, imaging experts and other professionals works together to manage the diagnosis and treatment of heart arrhythmias. We offer expertise in cardiac device management, including device implantation, lead extractions and medical management. Our state-of-the-art equipment allows physicians to use leading-edge technologies to perform procedures.
Learn more about our performance outcomes.