Key Points

• An implantable cardioverter defibrillator (ICD) is a small device that's placed in your chest or abdomen to help control life-threatening, irregular heart rhythms (called arrhythmias).
• 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. The device also will deliver high- or low-energy electrical pulses or shocks to the heart when it beats irregularly.
• An ICD isn't the same as a pacemaker. A pacemaker can only give off low-energy electrical pulses to correct certain irregular heartbeats. An ICD can give off the high-energy electrical pulses needed to correct dangerous arrhythmias in the lower chambers of the heart (ventricles).
• Your doctor may recommend an ICD if he or she sees signs of an irregular ventricular arrhythmia (or heart damage that would make one likely). He or she also may recommend an ICD if you survive sudden cardiac arrest.
• Surgery to place an ICD usually takes a few hours. After this minor surgery, you may have mild pain; over-the-counter medicines can usually relieve it. Consult your doctor before taking any pain medicine.
• The most common problem with ICDs is that they give pulses too often or when they aren't needed. Doctors can reprogram ICDs or prescribe medicines so the pulses occur less often. There are other rare risks 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 your ICD gives only last a second and feel like a thumping or painful kick in the chest, depending on their strength. Your doctor may give you medicine to lower 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 any vigorous exercise or heavy lifting for a short period after your surgery. After you have 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.