When is an Implantable Loop Recorder useful?
In many patients, symptoms of light-headedness, palpitations or fainting may be caused by abnormal heart rhythms. We can often determine if abnormal heart rhythms are the cause of these symptoms by having patients wear an external heart monitor such as a holter monitor or a loop monitor. These monitors attach to the skin of patients with small stickers. These monitors are very helpful for patients who are having frequent symptoms. They are less practical for patients who are having symptoms only once or twice a year. For patients who are experiencing significant but infrequent symptoms, we can offer an implantable loop recorder.
How does an implantable loop recorder work?
An implantable loop recorder (ILR) is a battery operated heart rhythm monitor which is implanted under the skin on the chest near the sternum (breastbone). The ILR is smaller than a BIC cigarette lighter and the battery lasts more than one year. When implanted, the device constantly monitors the heart rhythm and automatically keeps a record of the rhythm when the heart rate goes too slowly, too fast. Additionally, the patient can tell it to record with a small remote activator. The results of this monitoring can be down-loaded in the cardiologist’s office to a special laptop computer called an interrogation device.
How is an ILR placed?
Placement of an ILR is a minor surgical procedure that takes place in the hospital. In preparation for the procedure, the patient should have nothing to eat or drink after midnight the night before except for sips of water with necessary medications. The procedure is performed under local anesthesia, usually with light sedation. The procedure is performed under sterile conditions and takes about one hour.
What are the potential complications?
The risk of any serious complication with this procedure is well less than 1 in one 100. Patients will sometimes develop a minor skin infection at the site of the procedure that generally responds to oral antibiotic. Rarely, the infection requires removal of the loop monitor.
What is the recovery?
Typically, the patient can go home one or two hours after the implantation ideally with someone else as a driver. A driver is absolutely necessary if sedation is given. Discomfort from the implantation is usually mild and easily controlled with oral pain relievers. The wound is about one inch long and requires minor care for one week post-operatively. The wound should be observed by the cardiologist about one week after the implantation.
Are there any restrictions when the device is in place?
There is no concerning interaction with cell phones, microwave ovens, security devices or most medical testing. Magnetic resonance imaging (MRI) is not dangerous but may affect the device settings or recordings. Ideally, the cardiologist should down-load recordings prior to the MRI and reset the device after the MRI.
What finally happens to the device?
When a diagnosis is made or when the ILR battery is depleted the device is easily removed under local anesthesia with sterile conditions in the Electrophysiology laboratory with a procedure quite similar the that at the time of implantation. Only a small scar remains.