An insertable cardiac monitor (ICM), also known as an implantable loop recorder (ILR), is a long-term heart monitoring device. This miniaturized device is implanted under the skin to continuously record the heart’s electrical activity over long periods of time ranging from a few months to several years, depending on the model.
This technology is particularly useful for diagnosing intermittent heart disorders that are difficult to detect with more traditional monitoring methods, such as the electrocardiogram.
How does an insertable cardiac monitor work?
An insertable cardiac monitor is a compact device, similar in size to a USB memory stick, that is implanted under the skin, typically in the pectoral region.
The implantation of the ICM is a minimally invasive procedure performed under local anesthetic that lasts about 15 to 30 minutes. A small incision is made to insert the device. Once it is properly placed, the incision is closed with a few stitches. Patients usually return home the same day.
Once the device has been inserted, it will start to continuously record the heart’s electrical activity. Unlike portable, external Holter monitors that record information for 24 to 48 hours, insertable cardiac monitors can be used for several months or even several years. Some models can record information for up to three years.
What are the benefits of an insertable cardiac monitor?
Certain heart conditions, such as arrhythmias, can be challenging to diagnose due to their episodic nature. Patients may experience symptoms irregularly and when they do occur, it is often impossible to perform an immediate examination.
Standard electrocardiograms only capture the heart’s electrical activity over a short period of time, which limits their ability to detect transient arrhythmias.
Similarly, while traditional ambulatory Holter monitors offer continuous monitoring over 24 to 48 hours, this is not sufficient for diagnosing rare episodes. This is why insertable cardiac monitors are such a valuable tool.
What are the different types of insertable cardiac monitors?
There are two main types of insertable cardiac monitors:
- Standard models continuously monitor heart activity to detect arrhythmias over a period of months or years. They are mainly used to diagnose rare heart events like atrial fibrillation. These models offer a long operational life of up to three years.
- Connected insertable cardiac monitors. These advanced models come with wireless communication capabilities, enabling real-time data transmission to medical staff. They allow for proactive monitoring and send automatic alerts if irregularities are detected, which enhances treatment responsiveness.
What precautions should be taken?
Living with an insertable cardiac monitor does not pose any particular risks.
However, to ensure good quality recordings, it is best to take some precautions, such as keeping phones, tablets and computers away from the device. They should ideally be kept at least 15 centimeters away. Most household appliances will not cause any issues, but it is best to stay at least 60 centimeters away from induction cooktops.
Reviewed and approved by Lyric Institute’s cardiac pacing team
