Meaning of "sick-fit"

I recently came across with a religious text of the english Puritan theologian Edward Polhill (1622-1694). Here is a passage from it:

"Satan may hold up his pardoned sins, as it were in their old guilt; the arrows of God may stick fast in him, and bring qualms and sick-fits upon his conscience: but at that day his comforts shall be unvariable; a nightless day, and a cloudless horizon;"

I would like to know the meaning of the word "sick-fits". I am not a native english speaker and could not find that idiom in any dictionary.