An implantable cardioverter-defibrillator (ICD) is a device placed in patients who have had a cardiac arrest or are at high risk of having one. The ICD is able to monitor a patient’s heart and detect if and when the heart beats abnormally.

How it works

“If the heart goes out of rhythm, the ICD will do one of two things,” said Marshfield Clinic Health System cardiologist Dr. Param Sharma. “First it will try to pace the heart and stop the arrhythmia. If that does not work, the ICD sends an electric shock to the heart to restore a normal rhythm.”

When an electrical shock is delivered by the ICD people will feel it, Sharma said. If you receive a shock, you should seek medical attention.

A relatively minor procedure

Generally, the ICD is placed under the skin on the left side of the chest. Wires run from the device to the heart. Those wires send signals to the ICD about how the heart is beating. The procedure to place the ICD is relatively minor.

“It may take an hour or so to place the implant,” Sharma said. “Patients then stay overnight in the hospital and go home the next day.”

The procedure to implant the ICD is low risk, Sharma said. It is done under conscious sedation so patients are awake, but are given medication to help relax and to block pain. Once implanted, the ICD relays information about the patient’s heart back to the care team so the condition of the heart can be monitored even when the patient is at home.

Frequent follow-up care and some limitations

Sharma said the battery in the ICD is good for about six to eight years. Patients with an ICD require frequent follow-up appointments to make sure the implant is working properly.

Sharma said while ICDs are life-saving devices they do come with some limitations.

“There may be limitations on driving. There are some restrictions in terms of certain types of machinery or tools patients won’t be able to use when they have this implant,” Sharma said.

If you have questions or concerns about your heart health, talk with your provider.