Heart grew up on a ranch in San Luis Obispo, California and studied ballet as a child.

Heart danced at a Canoga Park strip club's amateur night at age 19 on a whim. While she was there she was recruited and subsequently met with agent Derek Hay of L.A. Direct Models in August of 2005. Her first on-camera appearance was in a scene for Shane's World. She signed with Vivid soon January of 2006 and was with them for nearly a year.

Heart rapidly became one of the most popular porn stars of 2005-2006 due to her pretty girl-next-door looks and her giggly personality. She gained further fame and popularity appearing in Jenna Jameson's American Sex Star contest, which she controversially lost.

Heart was introduced to fellow performer Scott Nails at an party about a month after she had entered the business. They became a couple soon after. Heart left Vivid after she told them that the only guy she wished to work with on camera was Nails; Vivid already had one actress who did only girl-girl, and they did not care to have Heart signed to work exclusively with one guy. In December of 2006, Lacie signed with Digital Playground.

As of May 2007, Lacie has breast implants.[citation needed]

As of June 2007 Heart lives in Arizona and commutes to Los Angeles to film; when asked why she does not live in Los Angeles, Heart replied "I think there's too many people, and I don't like traffic." She has stated that she plans to continue making adult films while she goes to school, then become a museum curator afterwards.