Biochemical pacemaker will appear

Gregory Benford : science fiction author and astrophysicist
The Pacific hagfish has three hearts, one of which has no nerve connections to the body. Dr. David Jensen discovered that this nerveless heart is kept beating by a powerful biochemical pacemaker, eptatretin, which may replace implanted electronic pacemakers as a treatment to regularize the heartbeat of people with faulty cardiac nerves

GREGORY BENFORD, Popular Mechanics, (2012), "The Future That Never Was: Pictures from the Past', [online], Available: