The daughter of Eric Garner -- whose death at the hands of an NYPD officer arresting him over untaxed cigarettes sparked national outrage -- is reportedly in a coma after suffering a heart attack.

Erica Garner, who has become an advocate against police brutality in her own right, had a heart attack Saturday night and is on life support. The 27-year-old mother of 2 went into cardiac arrest and is reportedly unable to breathe on her own.

Erica is on life support in ICU at a Brooklyn hospital ... this according to the New York Daily news, which first reported the news.

Eric Garner died in 2014 after an NYPD officer placed him in a chokehold while trying to arrest him on Staten Island. The officer in question was not indicted despite using the banned technique.