Leadless pacing shows promise
The second study examined a novel approach that modified the control algorithm of the Micra leadless single-chamber pacing device, approved for U.S. marketing in 2016, so that it used information collected by a built-in accelerometer to detect atrial contractions and produce atrial-ventricular (AV) synchrony in patients with AV block.
The MARVEL (Micra Atrial Tracking Using a Ventricular Accelerometer) study enrolled 70 patients at 12 centers worldwide and collected evaluable data from 64 patients. The average time spent in AV synchrony using this AV pacing was 87% in all patients, with an 80% average rate of AV synchrony in the 33 enrolled patients who had high-degree block, said Larry A. Chinitz, MD, professor of medicine and director of the Heart Rhythm Center at New York University Langone Health. Concurrently with his report at the meeting, the results also appeared in an article online (Heart Rhythm. 2018 May 11. doi: 10.1016/j.hrthm.2018.05.004).
Mitchel L. Zoler/MDedge News
Dr. Larry A. Chinitz
The current leadless pacemaker is very limited as a single-chamber pacing device because it can only help patients who have permanent atrial fibrillation and a slow ventricular response and hence only need single-chamber pacing, about 14% of all patients who need cardiac pacing, said Dr. Chinitz. Using the accelerometer information appears to make the Micra device suitable for the much larger number of patients who have AV block. “You effectively have dual-chamber pacing but with a single pellet. This is a simple and attractive way to do it,” Dr. Day commented. “You get a two-for-one” that potentially could triple the number of patients who could benefit from the Micra leadless device, he estimated.