Key Points

• An implantable cardioverter defibrillator (ICD) is a small device that's placed in your chest or abdomen. This device uses electrical pulses or shocks to help control life-threatening arrhythmias (irregular heartbeats).
• An ICD has wires with electrodes that connect to one or more of your heart's chambers. The ICD will continually monitor your heart rhythm. If the device detects an abnormal heart rhythm, it will use low- or high-energy electrical pulses to restore a normal rhythm.
• An ICD isn't the same as a pacemaker. A pacemaker can only give low-energy electrical pulses to correct certain irregular heartbeats. An ICD can give the high-energy electrical pulses needed to correct dangerous arrhythmias in the heart’s lower chambers, the ventricles.
• Your doctor may recommend an ICD if you’re at risk for a ventricular arrhythmia or if he or she sees signs of a ventricular arrhythmia (or heart damage that would make one likely) on test results. He or she also may recommend an ICD if you survive sudden cardiac arrest or are at high risk for the condition.
• Surgery to place an ICD usually takes a few hours. After this minor surgery, you may have mild pain; over-the-counter pain medicines usually can relieve it. Talk to your doctor before taking any pain medicine.
• The most common problem with ICDs is that they can sometimes give electrical pulses that aren't needed. Doctors can reprogram ICDs or prescribe medicines so the electrical pulses occur less often. Other, rare risks are linked to the ICD surgery, such as infection and bleeding.
• The low-energy electrical pulses your ICD gives off aren't painful. You may not notice them, or you may feel a fluttering in your chest.
• The high-energy pulses or shocks your ICD gives only last a fraction of a second and feel like a thumping or painful kick in the chest, depending on their strength. Your doctor may give you medicine to decrease the number of arrhythmias you have. This may reduce the number of high-energy pulses sent to your heart.
• Once you have an ICD, you have to avoid close or prolonged contact with electrical devices or devices that have strong magnetic fields. You also need to avoid medical procedures that can disrupt your ICD. Let all of your doctors, dentists, and medical technicians know that you have an ICD.
• Your doctor may ask you to avoid vigorous exercise and heavy lifting for a short time after your surgery. After you’ve fully recovered from surgery, discuss with your doctor how much and what kinds of physical activity are safe for you.
• Have your ICD checked regularly. Some ICD functions can be checked remotely through a telephone call or computer connection to the Internet. Your doctor may ask you to come to his or her office to check your ICD.
• ICD batteries have to be replaced every 5 to 7 years. The wires of your ICD also may have to be replaced eventually. You doctor can tell you whether you need to replace your ICD or its wires.