The implantable loop recorder (ILR) is a small, subcutaneous device designed for long-term monitoring of the heart’s electrical activity. Its primary function is to act as a continuous electrocardiogram (ECG) recorder, tracking the heart rhythm for up to three or four years. This monitoring is used when a patient experiences infrequent symptoms, such as unexplained fainting, palpitations, or dizziness, that are too fleeting to be captured by standard, short-term monitors. By recording the heart’s rhythm over an extended period, the ILR helps physicians diagnose sporadic arrhythmias, including atrial fibrillation, which can be difficult to detect and may increase the risk of stroke. The device is placed just beneath the skin, allowing patients to resume normal activities while it captures the diagnostic data.
Pre-Procedure Steps and Preparation
Preparation for an ILR insertion procedure begins with a discussion between the patient and the cardiology team regarding specific medical instructions. Patients are typically advised about fasting requirements, often needing to avoid food for several hours before the procedure, though sips of water may be allowed for taking necessary medications. If the procedure involves mild sedation, a driver must be arranged, as operating machinery or making important decisions is restricted for 24 hours afterward.
Preparation involves adjusting current medications, particularly blood thinners. While some blood thinners may be continued, others, such as warfarin, are often temporarily stopped several days prior, sometimes requiring a temporary switch to an alternative injectable medication. Patients must also inform the medical staff of all current prescriptions, over-the-counter drugs, and any known allergies. On the day of the procedure, patients should report any signs of infection, such as fever or cold symptoms, which could postpone the procedure.
Step-by-Step Insertion Process
The insertion of an implantable loop recorder is an outpatient procedure, typically performed by an electrophysiologist in a specialized cardiac laboratory. The entire process is swift, often taking only about 10 to 30 minutes to complete. To ensure patient comfort, the procedure begins with the administration of a local anesthetic injection to numb the skin on the upper chest, usually on the left side.
Once the area is numb, a small incision, often less than one centimeter, is made in the skin. The physician creates a small subcutaneous pocket beneath the skin’s surface to house the device. The ILR device, which is about the size of a flat AA or AAA battery, is then inserted into the pocket. For certain newer models, the device may be inserted directly using a specialized tool in a technique similar to an injection, minimizing the size of the initial cut.
After the device is in place, its function is immediately tested to confirm it is successfully picking up the heart’s electrical signals. The incision is then closed using either dissolvable sutures, surgical glue (like Dermabond), or adhesive strips (Steri-Strips). A sterile dressing is applied to the wound site to protect it from infection.
Immediate Post-Procedure Care and Monitoring
Following the insertion, patients recover for an hour or two before being discharged home the same day. The care team provides detailed wound instructions, which usually involve keeping the incision site clean and dry for the first few days to a week to reduce the risk of infection. Patients are advised to avoid soaking the wound; baths or swimming are restricted until the site is fully healed.
While the implant site may be sore and cause bruising for a few weeks, patients are generally able to resume most regular activities quickly. Strenuous activities, such as heavy lifting or intense exercise, are usually restricted for about seven to ten days. Patients are taught how to use a handheld activator or a smartphone app for monitoring.
If a patient experiences symptoms like dizziness or palpitations, they are instructed to hold the activator over the ILR and press a button. This action bookmarks the specific heart rhythm data for the physician to review. Many modern ILRs also work with a home monitoring system, which automatically and wirelessly transmits recorded data to the clinic on a regular schedule, often nightly.