The best replacement for heartbeat is pulse.

The best alternatives to heartbeat are rated as following:
★★★★★  pulse
★★★★  heart beat
★★★  keepalived
★★★  pacemaker
★★  corosync
★★  openais
★★  heart rate
★  heartbeat
★  fetal pole at 6 weeks
★  baby kicking
★  placenta
★  boy heartbeat
★  pulse rate
★  ucarp
★  murmur
  call me maybe
  baby girl heartbeat
  fetal pole at 5 weeks
  keepalives
  boys heartbeat
  heart murmur
  fetal pole at 7 weeks
  atrial fibrillation
  fetus
  girl heartbeat
  heart palpitations
  silencer
  palpitations
  mothers heartbeat
  palpitation
  pulse beat
  keep alive
  afib

Your alternative for heartbeat is not listed? Suggest!
Speaking about heartbeat, one probably shouldn't forget about ultrasound.

Other search terms related to heartbeat and their ratings are:
★★★★★ ultrasound
★★★ doppler at 10 weeks
★★★ doppler at 9 weeks
★★★ doppler at 12 weeks
★★★ fetal pole
★★★ pulse
★★★ breathing
★★ pacemaker
★★ ectopic pregnancy
★ molar pregnancy
★ doppler at 8 weeks
★ doppler at 11 weeks
★ heart tattoo
★ yolk sac
You have in mind a companion for heartbeat and it is not yet here? Propose!



Google Trends

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heartbeat
pulse
heart beat