Implantable cardioverter-defibrillators (ICDs)
About this test
An implantable cardioverter-defibrillator (ICD) is a small battery-powered device placed in the chest. It detects and stops irregular heartbeats, also called arrhythmias. An ICD continuously checks the heartbeat. It delivers electric shocks, when needed, to restore a regular heart rhythm.
Why it's done
An ICD constantly checks for irregular heartbeats and instantly tries to correct them. It helps when there is a sudden loss of all heart activity, a condition called cardiac arrest. An ICD is the main treatment for anyone who has survived cardiac arrest. The devices are increasingly used in people at high risk of sudden cardiac arrest. An ICD lowers the risk of sudden death from cardiac arrest more than medicine alone. Your heart doctor may recommend an ICD if you have symptoms of an irregular heart rhythm called sustained ventricular tachycardia. Fainting is one of the symptoms. An ICD also may be recommended if you survived cardiac arrest or if you have: A history of coronary artery disease and a heart attack that has weakened the heart. An enlarged heart muscle. A genetic heart condition that increases the risk of dangerously fast heart rhythms, such as some types of long QT syndrome.
Risks and complications
Possible risks of implantable cardiac defibrillators (ICDs) or ICD surgery may include: Infection at the implant site. Swelling, bleeding or bruising. Blood vessel damage from ICD wires. Bleeding around the heart, which can be life-threatening. Blood leaking through the heart valve where the ICD lead is placed. Collapsed lung. Movement of the device or leads, which could lead to a rip or cut in the heart muscle. This complication, called cardiac perforation, is rare.
How to prepare
Before you get an ICD , several tests are done to check your heart health. Tests may include: Electrocardiogram (ECG or EKG). An ECG is a quick and painless test that checks the heartbeat. Sticky patches called electrodes are placed on the chest and sometimes the arms and legs. Wires connect the electrodes to a computer, which displays or prints the test results. An ECG can show if the heart is beating too fast or too slowly. Echocardiogram. This imaging test uses sound waves to create moving pictures of the heart. It shows the size and structure of the heart and how blood flows through the heart. Holter monitoring. A Holter monitor is a small, wearable device that keeps track of the heart rhythm. You typically wear it for 1 to 2 days. A Holter monitor may be able to spot irregular heart rhythms that an ECG missed. Wires from sensors that stick to the chest connect to a battery-operated recording device. You carry the device in a pocket or wear it on a belt or shoulder strap. While wearing the monitor, you may be asked to write down your activities and symptoms. Your health care team may compare your notes with the device recordings and try to figure out the cause of your symptoms. Event monitor. This portable ECG device is intended to be worn for up to 30 days or until you have an arrhythmia or symptoms. You typically press a button when symptoms occur. Electrophysiology study, also called EP study. This test may be done to confirm a diagnosis of a fast heartbeat. It also can identify the area in the heart that's causing an irregular heartbeat. The doctor guides a flexible tube called a catheter through a blood vessel into the heart. More than one catheter is often used. Sensors on the tip of each catheter record the heart's signals.
Understanding your results
After getting an ICD , you need regular health appointments to check your heart and the device. The lithium battery in an ICD can last 5 to 7 years. The battery is usually checked during regular health appointments, which should occur about every six months. Ask your health care team how often you need a checkup. When the battery is nearly out of power, the generator is replaced with a new one during a minor outpatient procedure. Tell your doctor if you have any shocks from your ICD . The shocks can be unsettling. But they mean the ICD is treating a heart rhythm problem and protecting against sudden death.
Disclaimer: August is a health information platform and its responses don't constitute medical advise. Always consult with a licenced medical professional near you before making any changes.