It’s a third smaller than a pencil-thin triple-A battery, monitors heart rhythm continuously for up to three years and was recently implanted in a patient for only the second time in Illinois by a physician at Advocate Christ Medical Center.
Called an “implantable loop recorder,” the device can be pushed through a small puncture hole in the skin and positioned at a 45-degree angle on the rib cage over the heart in a procedure that takes less than 10 minutes and requires little or no sedation other than a local anesthetic at the site of the puncture, said Jeffrey Neiger, MD, a cardiologist who specializes in electrophysiology and who performed Christ Medical Center’s first implantation of the device. “Patients do not even feel it’s there.” he said.
The mini-monitor is proving most effective for patients who experience episodes of syncope (fainting spells) or who have suffered a cryptogenic stroke (stroke with no identifiable cause), because a heart rhythm abnormality that could be causing these problems might only be detectable during an extended monitoring period, Dr. Neiger explained.
“Until now, monitors were limited. The external holter monitor, which has to be worn and records heart rhythm through electrodes placed on the skin, is bulky, sometimes irritating to the skin and provides data for only 24 to, perhaps, 72 hours at best. Another external monitor, called an event monitor, is worn for up to a month. And, the older, implantable monitor is about as large as a pack of gum, heavier than the newer model, and requires a lengthier procedure to implant,” Neiger said.
“For a person who experiences only a few episodes of syncope during a 12-month period, a few days, even a month’s worth, of heart monitoring may not prove sufficient to pinpoint the problem,” he said.
The mini-monitor wirelessly signals a small unit, about the size of a land-line phone handset, which is simply plugged into an outlet in the patient’s home. The unit then uses the cellular phone network to send the patient’s heart rhythm information to a computer server for later downloading and review by the patient’s physician. The unit can be programmed to send an alarm when an adverse heart rhythm is detected.
The system’s use of wireless, cellular networks also ensures that the heart-monitoring data being recorded and sent is of higher quality than what the older monitors can provide, Neiger said.
Christ Medical Center was only the second institution in the state to implant the new heart monitor after its approval by the federal Food and Drug Administration earlier this year, Neiger said, adding that the device took him only about 10 minutes to insert and position in his first patient. “I anticipate eventually being able to perform the procedure in about five minutes,” he said.
Because of the ease in implanting the new device, its convenience to patients and its ability to collect heart data during a several-year period, Neiger anticipates that, one day, physicians in a hospital emergency department may be able to implant these mini-monitors when a patient arrives for treatment following a syncope episode.
“For patients who have experienced a stroke with no immediate, attributable cause, these new monitors should prove especially important,” he stated. “Up to 30 percent of patients who have suffered a cryptogenic stroke have been later diagnosed with A-fib (atrial fibrillation, a condition that causes abnormal heart rhythms).”
Neiger added that the device is made to continue monitoring even when a patient travels internationally.
— Advocate Christ Medical Hospital