The implantable loop recorder (ILR) is a small device which is implanted just under the skin of the chest to the left of your breastbone. The actual size is 0.5 ounces and 61mm by 19mm by 8mm. The ILR has the ability to record the electrical activity of the heart in two ways. First, it is activated according to heart rate ranges set on the device by your physician. If the heart rate drops below the lowest value set, the ILR will automatically start to record. In the same way, if the heart rate rises over the highest value set, the ILR will also record without the patient’s knowledge. The second way it records is through a “patient activator” whereby you can trigger a recording by pushing a button on the activator. The activator can be used when you experience symptoms such as skipped beats, lightheadedness, or dizziness. To start a recording, simply place the patient activator over the ILR and press the button. A green light will flash when recording is successful. The recording is stored in the ILR itself. Your physician can view both the automatic and triggered events during a routine office visit using a special programmer, which looks similar to a laptop computer.
ILRs are recommended for patients who experience symptoms such as syncope (fainting), seizures, recurrent palpitations, lightheadedness, or dizziness. The ILR is best used in patients who experience these serious symptoms regularly but not often enough to be captured by a 24-hour or 30-day external monitor. Because of the two-year battery life of the ILR, patients will experience extended and constant monitoring, giving the physician ample opportunity to capture any abnormal heart rhythm.
The ILR is placed by your electrophysiologist in a procedure lab under local anesthesia. Conscious sedation can be used but is generally not necessary. A small incision (about 3-4 cm or 1.5 inches) is made just to the left of the breastbone. A pocket is created under the skin, and the ILR is placed in this pocket. No wires are inserted into the heart. The incision is closed with dissolvable sutures. Patients can go home the same day of the procedure with almost no restrictions on activity or work. The ILR is completely safe under the skin for more than the life of the battery without any adverse effects to the patient’s health or well being.