A cardioid pedal curve is the locus of the feet of the perpendiculars from a fixed pedal point to the tangent lines of a cardioid.
The pedal curve of the cardioid with respect to the center of its conchoidal circle is the limaçon trisectrix (Ferréol).
For the special pedal point of the cardioid cusp, the pedal curve of the cardioid
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(1)
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(2)
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is
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(3)
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(4)
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which is Cayley's sextic (Gray 1997, pp. 119-120).
For an arbitrary pedal point 
, the signed area of
one complete traversal with the plus-cosine cardioid
convention above is
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(5)
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For pedal curves with self-intersections or repeated coverage, this signed area need not equal the area of the union of the bounded regions.
