Michael Clarke Duncan is currently in intensive care at a Los Angeles, Calif., hospital after going into cardiac arrest on Friday morning.
Duncan's girlfriend of two years, Omarosa Stallworth, reportedly saved the actor's life after finding him the 54-year-old unconscious in his home, according to TMZ.
A distressed Stallworth called 911 and performed CPR on the "Green Mile" star in an effort to resuscitate him- a quick thinking move which some say saved his life.
Duncan was quickly transported to a local hospital shortly after 2 a.m., where he was immediately admitted to the ICU.
His heart rate is now said to be stable, and he is currently being treated with heart medication while doctors perform tests to determine the cause of his heart failure.
Stallworth, 38, reportedly met Duncan in the produce section of a Whole Foods grocery store in 2010.
She rose to fame six years prior due to her role on NBC's reality TV Series, "The Apprentice," where she was portrayed as a villain.
Duncan, who once worked as a Hollywood bodyguard for celebrities including Will Smith and Notorious B.I.G, rose to stardom in 1999 for his breakout role as John Coffey in "The Green Mile."
The Academy Award nominee has since appeared in a string of films including "Planet of the Apes," "The Scorpion King," and "Daredevil."
The 6-foot-5-inch actor won praises from animal rights group PETA in 2009 when he publicly vowed to stop eating meat, claiming that vegetarianism was beneficial to his health and that the strict diet increased his strength.
It is unclear how long Duncan will remain in the hospital, although it has been confirmed that Stallworth will stay by his side.
Fans of the actor flocked to social networking site Twitter to offer their well wishes.
"i hope my brother Michael Clarke Duncan will be ok," Russell Simmons tweeted.
"Best wishes for a speedy and full recovery to the Champ, Michael Clarke Duncan. Get well my friend," Erik Stolhanske tweeted.
"Sending love to #PETA friend, Michael Clarke Duncan, & his family. Our thoughts are with you Big Mike, & wish for a speedy recovery!" Michelle Cho tweeted.