In March 2009, Karan, a 53-year-old mom from New Jersey, got on the treadmill, like she does every morning. Only this time, something was different. "I, all of a sudden, felt horrible," she says. "I had a burning across my chest. I couldn't breathe, so I thought, ''Maybe it's my asthma.'"

Then, Karan says she started having jaw pain, which triggered a memory of something Dr. Oz once said. "I remember from your show that you said [jaw pain] was a symptom of a heart attack ," she says. "So I woke my husband up and said, ''Come on, we've got to go to the hospital.'"

Thankfully, Karan survived to share her story with Dr. Oz. "I have to thank you from the bottom of my damaged heart for giving me my life," she says.