pacemaker

nouns

a leading instance in its field
"the new policy will be a pacesetter in community relations"
pacemaker, pacesetter
a specialized bit of heart tissue that controls the heartbeat
SA node, cardiac pacemaker, pacemaker, sinoatrial node
an implanted electronic device that takes over the function of the natural cardiac pacemaker
artificial pacemaker, pacemaker
a horse used to set the pace in racing
pacemaker, pacer, pacesetter