The tech appears impressive but an 8 person clinical trial is not an overly large metric to base the success on.
A clinic research paper was published last year by the European Society of Cardiologists titled
"European experience with a first totally leadless cardiac resynchronization therapy pacemaker system" (google is your friend) which goes into greater detail about the tech and the actual trial and has some interesting comments in the paragraph at the end titled "Limitations" if anyone is up for some light reading
