Possible Clues:

• Heart regulatory device
• Are pack, perhaps, keeping me back? Certainly not!
• By leave of the composer, one corrects the beat
• Trendsetter may be taken to heart
• He sets the rate, of course
• Member of UN team ignores one European leader at the start
• Early leader should be in good heart?
• The leader unfolds map with a creek to be seen
• Device inserted in body to strengthen heartbeat
• Device correcting heart rhythms