The best replacement for cardioid is supercardioid.

The best alternatives to cardioid are rated as following:
★★★★★  supercardioid
★★★★★  omnidirectional
★★★★★  hypercardioid
★★★★  omni
★★★  condenser
★★  omni lavalier
★★  omnidirectional lavalier
★  limacon
★  multi pattern
★  condenser microphone
★  supercardioid pattern
★  cardioid
★  super cardioid
  unidirectional
  supercardoid
  omnidirectional microphone
  condenser mics

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

Other search terms related to cardioid and their ratings are:
★★★★★ limacon
You have in mind a companion for cardioid and it is not yet here? Propose!



Google Trends

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cardioid
supercardioid
omnidirectional