Cambridge Heart, Inc., a Tewksbury, Massachusetts firm, is reporting that it has completed the development of an OEM (original equipment manufacturer) module of its Microvolt T-wave Alternans (MTWA), and is now seeking FDA’s 501(k) to start marketing its technology. According to MassDevice, the company is planning to shift its focus from sales to physicians and hospitals, so it can now start developing “an OEM version that other manufacturers could incorporate into their own products.”
As some of you might remember from our previous coverage of this technology, the Microvolt T-wave Alternans (MTWA) stress test, that “looks at beat-to-beat fluctuation in the amplitude of the T-wave at a microvolt level,” was initially developed by MIT with support from NASA’s Johnson Space Center and the National Space Biomedical Research Institute in Houston, Texas. The technology has shown promise in a number of studies by predicting increased patient risk to develop life threatening ventricular arrhythmias or sudden cardiac arrest. One example of this would be positive results from the Alternans Before Cardioverter Defibrillator (ABCD) trial, that were presented at the American Heart Association’s 2006 Scientific Sessions (1).
It will now be interesting to see if major manufacturers try to incorporate MTWA technology into their monitors, and whether MTWA will make inroads into other clinical areas, such as advanced perioperative anesthetic or critical care monitoring, or preoperative evaluation.
Here’s more about the MTWA technology:
Microvolt T-Wave Alternans is defined as an alternation in the morphology of the T-wave in an every other beat or AB-AB pattern. It has long been associated with ventricular arrhythmias and sudden death. First recognized nearly a century ago, visually discernible alternans were linked to the rapid onset of ventricular tachyarrhythmias.
Research conducted in the early 1980’s by Dr. Richard Cohen and his colleagues at MIT explored the idea that visually indiscernible alternans may be equally significant. These efforts established a link between visually imperceptible alternans at the microvolt level and susceptibility to arrhythmias and showed alternans to be a heart rate dependent phenomenon. In addition, they developed a methodology, known as the Spectral Method, which allowed measurement of alternans at the level of one microvolt.
This method was refined to create our proprietary Analytic Spectral Method® which uses Micro-V Alternans Sensors™ that are specially designed, high-resolution, noise canceling sensors to detect minute heartbeat variations, measured at as little as one-millionth of a volt. This permits the measurement of alternans even in the presence of the noise typically encountered during exercise stress testing. These sensors allow the recording of up to four ECG signals from the same anatomical site as well as electrode-skin impedance and respiratory signal. An adaptive noise reduction algorithm combines these signals to create an enhanced ECG signal to expose previously indiscernible T-Wave alternans.
The Microvolt T-Wave Alternans test is a provocative, non-invasive, easy to perform, diagnostic test. By taking detailed ECG measurements during rest, exercise, and then rest again, the HearTwave® II System can identify the presence of Microvolt T-Wave Alternans.
In most situations, the test takes less than 30 minutes to perform. Following the placement of fourteen sensors – 7 Micro-V Alternans Sensors and 7 standard electrodes – in the Frank-lead configuration, the electrodes are connected to the digital ECG amplifier that leads back to the Microvolt T-Wave Alternans enabled system. At the beginning of the test, the patient is directed to begin walking on a treadmill to raise the heart rate. Patients who are unable to exercise can have their heart rates elevated pharmacologically to achieve the higher rate needed for a successful test.
Full story: Cambridge Heart asks FDA for 510(k) clearance for OEM device…
Press release: Cambridge Heart Completes Development of New MTWA Module …
Product page: HearTwave® II Microvolt T-Wave Alternans™ System …
Technology info page: Microvolt T-Wave Alternans …
Flashbacks: Microvolt T-Wave Alternans Testing Shows Promise for Predicting Sudden Cardiac Death; HearTwave® II Microvolt T-Wave Alternans System ;