The implantable cardiac monitoring (ICM) sector saw an uptick of activity last week as two companies competing in the space reported regulatory/commercialization achievements with their respective technologies. Transoma Medical (St. Paul, Minnesota) received FDA clearance for its second-generation ICM product, Sleuth AT (Advanced Trending) cardiac monitoring system.

Also last week, Medtronic (Minneapolis) reported the commercial availability of its Reveal XT insertable cardiac monitor in the U.S. and the first U.S. implant of that device (Medical Device Daily, Feb. 12, 2009).

Transoma said its new device allows physicians to program the capture of electrocardiogram (ECG) strips at more frequent intervals than its previous device, putting more control in the hands of the physician.

The first-generation Sleuth product had three ways of capturing an ECG, Nestor Jaramillo, VP of sales and marketing at Transoma, told Medical Device Daily. First, when a patient felt a symptom (such as lightheadedness) they could push a button to tell the system to store the ECG strip during the time of the symptom; second, the system automatically captured and stored the ECG strip when the patient's heart rate is above or below physician-programmed limits; and third, the Sleuth would automatically capture an ECG every four hours.

The Sleuth AT captures an ECG the same as the predecessor device except that the new Sleuth can be programmed to capture a 20-second ECG strip every 7.5 minutes, or every 15 minutes, or every four hours, Jaramillo said. So, he said, if the physician wanted to monitor a patient for complex arrhythmias, including atrial fibrillation (AF), he will get a monthly report, looking at the patient for 20 seconds as often as every 7.5 minutes.

Transoma said the system includes an implantable loop recorder, a personal diagnostic manager (PDM), a base station and a 24/7 monitoring center operated by Medicomp (Chantilly, Virginia) and staffed by certified cardiac technicians who classify and notify physicians of the presence of a wide variety of cardiac arrhythmias such as ventricular tachycardia, bradycardia, supraventricular tachycardia and AF. If the cardiac technician observes a particularly concerning arrhythmia, the patient's physician will be contacted immediately, the company said.

Transoma describes the ICM as a small, thin device, about the size of a 50-cent piece (or the size of the smallest pacemakers), which continuously monitors the electrical activity of the heart. The cardiac monitor is implanted under the skin during a brief, simple, outpatient procedure, the company noted. The PDM is a hand-held, multipurpose device that automatically retrieves and stores relevant ECG data from the ICM, securely relays the information to the base station and then to the monitoring center. The physician also uses the PDM to program the ICM.

Similarly, Medtronic's Reveal XT and its Reveal DX insertable cardiac monitors are placed just under the skin of the chest area in a short outpatient procedure, and are also designed to capture an ECG during the actual episode. The patient can store an ECG by placing a hand-held, pager-sized assistant over the device, and pressing a button. Later, a physician analyzes the stored information, transmitted via the Medtronic CareLink Network or during an in-office patient visit, and determines whether the episode was caused by an abnormal heart rhythm.

Medtronic received Japanese regulatory approval for the Reveal DX in July, a device the size of a memory stick. The company said the device provides insight into syncope, unexplained fainting episodes (MDD, July 21, 2008).

Another Minnesota company in the ICM sector is St. Jude Medical (St. Paul, Minnesota), which reported FDA clearance of its Confirm ICM in September. That device is the size of a computer thumb drive and St. Jude said at the time that it is the smallest cardiac monitor available. St. Jude's device is also approved for syncope (MDD, Sept. 12, 2008).

Despite facing competition from Medtronic and St. Jude, Jaramillo said Transoma's device stands out against both of those companies' devices in its design and, importantly, memory capacity. According to Transoma the Sleuth AT has a "virtually unlimited memory capacity," which Jaramillo said is a significant advantage over competing devices.

"We think the market is significantly underpenetrated," Jaramillo told MDD. "Based on the calculations we have made, 100 to 150 patients come in every year with a syncope that, after the conventional testing, continue to be undiagnosed and that's just by the nature of the syncope."

Syncope is difficult to diagnose as episodes are often too infrequent and unpredictable for detection with conventional monitoring techniques such as ECG Holter monitors or external loop recorders.

"Some of these patients only faint two or three times a year," Jaramillo said. "They are in their normal routine, they could be driving, they could be at work. The physician wants to capture the ECG when it happens."

According to Peter Kowey, MD, chief of cardiology for Main Line Health, William Wikoff Smith Chair in CV Research at the Lankenau Institute (Wynnewood, Pennsylvania), the Sleuth AT "promises to provide an improved approach."

"The concept of the device, without memory constraints, automatically capturing frequent ECG strips which are then over-read at the monitoring center, may address the limitations and inaccuracies of existing devices used to assess complex arrhythmias such as atrial fibrillation," Kowey said in a Transoma news release.

Jaramillo said Transoma believes its technology brings a "totally new approach" to cardiac monitoring. "We are redefining cardiac monitoring in a way that physicians would be more attracted to implant this technology," he said.