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Diagnosing Cardiac Device Problems in Adults

People with heart rhythm disorders require ongoing management of cardiac devices, including pacemakers, loop recorders, and implantable cardioverter defibrillators, or ICDs. These devices are surgically implanted in the chest to help the heart pump blood to the body at regular rates. ICDs are designed to correct life threatening heart rhythms.

After surgery to implant a device, you visit NYU Langone’s Heart Rhythm Center for follow-up care and monitoring, typically every six months.

Some cardiac devices can be monitored remotely, using a special wireless transmitter. Remote monitoring often allows doctors to detect problems with implanted devices and heart rhythms sooner than office visits do. It also reduces the frequency of in-office evaluations.

Cardiac Device Monitoring

Regular monitoring of your pacemaker or ICD helps identify any problems that require adjustment or replacement of the device, including a failure to provide electrical impulses to the heart or incorrect sensing of the heart’s electrical activity. Monitoring with a loop recorder can help your doctor diagnose a heart rhythm disorder. Monitoring can take place in our offices or at your home.

In-office Monitoring

In your doctor’s office, a cardiac device technician places a wand over your device to transmit information to and from the device and a computer. This information tells your doctor how well the device is working and whether it needs to be reprogrammed to optimize the device’s function for you. The battery life and the condition of any wires are also checked.

These visits typically occur every six months. As the device nears its replacement time, your doctor may request more frequent monitoring to check the battery life. The device and the battery sealed inside it are replaced when there are about three months of normal function remaining.

Remote Monitoring

Depending on the device, you may be able to alternate in-office monitoring with telephone, cellular, or internet monitoring. Using special equipment provided to you at no charge, you can transmit information stored on your device to the Heart Rhythm Center, where it is downloaded and assessed.

Because the devices cannot be reprogrammed over the phone, office visits are still occasionally required, even if you have remote monitoring.

If you feel a shock from your ICD between checkups, contact your doctor immediately. He or she takes steps to make sure the device is working properly. If you feel multiple shocks or you are feeling very ill, call 911 or go to the nearest emergency room. Do not drive yourself.

If you experience fainting or heart palpitations, use your handheld device to capture information from your loop recorder and send it to your doctor, using your home monitoring system.

Medical Tests

Complications from the implantation of cardiac devices are uncommon, but may include infection, bleeding at the incision site, bruising, perforation of the heart by the leads—the insulated wires that connect the device to the heart—a blood clot in a vein, or a collapsed lung.

NYU Langone heart specialists administer antibiotics as a preventive measure during surgery to implant the cardiac device. However, infections can still occur. A person can develop a “pocket,” or localized infection near the device. Less commonly, he or she may develop a deeper infection called endocarditis, which can affect the bloodstream and the heart’s valves.

A weakened immune system, which may occur in people with cancer or those taking medications that affect the immune system, can also be a risk factor for infection.

Symptoms of infection include pain at the implant site, chills, fever, and redness and swelling around the skin that holds the device. Treatment may include intravenous (IV) antibiotics or those taken by mouth. However, when it’s a pocket infection or an infection in the bloodstream, the device is removed until the infection is eliminated.

Some people may need a temporary external pacemaker, which attaches to the heart through leads that extend through an incision in the chest, to keep the heart beating while the infection is cleared. Then, cardiac electrophysiologists implant a new, sterile device.

Blood Tests

If you have symptoms of an infection, your doctor tests your blood for bacteria, elevated levels of white blood cells, which fight infection, and inflammation markers, which are proteins that can signal various heart conditions.

Chest X-rays

An X-ray uses a small amount of electromagnetic radiation to create images of structures inside the body. If your doctor suspects there may be a problem with your cardiac device, he or she may order an X-ray of the chest.

These scans help determine if the device has slipped out of place, if the leads have become unattached or damaged, or if the leads have punctured the heart. A chest X-ray can also identify a collapsed lung.


Also called an EKG, an electrocardiogram is a painless, noninvasive test that measures the heart’s electrical activity to help your doctor assess its rate and rhythm. The doctor places small, painless electrodes on the chest, wrists, and ankles to send information about your heart to a machine, which prints out a graph of the heart’s electrical activity.

An EKG can help determine how well your cardiac device is regulating your heart’s electrical impulses. It also can reveal the status of your heart’s rhythm.


In this test, which is performed in your doctor’s office, a wand called a transducer is placed on your chest to send images of the heart to a computer using sound waves. Your doctor uses this test to check for blood clots and for abnormal material on the wires of the cardiac device, which is a sign of endocarditis, an infection of the heart and heart valves.

This test can also measure the strength of the heart muscle, the size of its chambers, and the condition of the valves.

Our Research and Education in Cardiac Device Management in Adults

Learn more about our research and professional education opportunities.