Implantable Cardiac Devices

Implantable cardiac devices can sometimes be used to help manage problems with a person’s heart rate or heart rhythm.

The heart has an electrical system (conducting system) that regulates the heart rate, made up of nodes (special clusters of conducting cells) and conduction pathways.

Problems with the electrical circuitry of the heart can include blocked signals or signals taking an abnormal path through the heart.

Cardiac rhythm management devices perform many functions, including monitoring for irregular heartbeat, synchronise heart rhythm to prevent heart failure, defibrillation and finding abnormal resting heart beat.

Types of implantable devices


A pacemaker is a small device that's placed under the skin in your chest to help control your heartbeat. It's used to help your heart beat more regularly if you have an irregular heartbeat (arrhythmia), particularly a slow one. Implanting a pacemaker in your chest requires a surgical procedure.

Depending on your condition, you might have one of the following types of pacemakers.

Single chamber pacemaker. This type usually carries electrical impulses to the right ventricle of your heart.

Dual chamber pacemaker. This type carries electrical impulses to the right ventricle and the right atrium of your heart to help control the timing of contractions between the two chambers.

Biventricular pacemaker. Biventricular pacing, also called cardiac resynchronization therapy, is for people with heart failure with abnormal electrical systems. This type of pacemaker stimulates the lower chambers of the heart (the right and left ventricles) to make the heart beat more efficiently.


An implantable cardioverter-defibrillator (ICD) is a small battery-powered device placed in your chest to monitor your heart rhythm and detect irregular heartbeats. An ICD can deliver electric shocks via one or more wires connected to your heart to fix an abnormal heart rhythm.

How an ICD works

When you have a rapid heartbeat, the wires from your heart to the device transmit signals to the ICD, which sends electrical pulses to regulate your heartbeat. Depending on the problem with your heartbeat, your ICD could be programmed for:

Low-energy pacing. You may feel nothing or a painless fluttering in your chest when your ICD responds to mild disruptions in your heartbeat.

A higher-energy shock. For more-serious heart rhythm problems, the ICD may deliver a higher-energy shock. This shock can be painful, possibly making you feel as if you've been kicked in the chest. The pain usually lasts only a second, and there shouldn't be discomfort after the shock ends.

Usually, only one shock is needed to restore a normal heartbeat. Sometimes, however, you might have two or more shocks during a 24-hour period.

Having three or more shocks in a short time period is known as an electrical or arrhythmia storm. If you have an electrical storm, you should seek emergency care to see if your ICD is working properly or if you have a problem that's making your heart beat abnormally.

Concerns regarding potential device-related complications should be discussed with the implanting physician. In the post-implant period, patients with cardiac rhythm management devices can expect to lead normal, active lives. However, caution must occasionally be exercised in certain situations, such as near appliances with electromagnetic interference. In the recent events, patients have been advised to keep their Apple iphones and devices atleast 6 inches away especially while charging.

Implanted medical devices deactivating when magnets are held over them isn’t anything new. In fact, it’s expected behaviour. The devices are built to deactivate when a magnet is held over them, and doctors should always inform patients about the risks and necessary precautions when they’re using an implanted medical device. Please note, incase of any issues with your cardiac devices, reach out to your GP or specialist.

If you or someone in your family has recently had heart surgery or plan on getting surgery in the near future, you can talk to us

Call our Help Line for a quick answer about your heart

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