pacemaker

Concise Oxford English Dictionary © 2008 Oxford University Press:
pacemaker/ˈpeɪsmeɪkə(r)/

▶noun

• 1 a competitor who sets the pace at the beginning of a race or competition.

  ■ a person who sets standards of achievement for others.

• 2 an artificial device for stimulating and regulating the heart muscle.

• 3 a part of an organ or of the body which controls rhythmic physiological activity.

– derivatives
pacemaking adjective & noun.