Lamar Odom's condition is rumored to be slightly improving, and the former NBA star's heart function is reported to be responding to treatment.

TMZ reported Odom's heart functions were "much better" on Friday, though sources later told the website some of the body movements Odom is now reported to be exhibiting may be involuntary.

The 35-year-old former NBA Sixth Man of the Year Award winner has been clinging to life ever since being rushed to a hospital emergency room earlier this week. Odom was found unconscious and unresponsive at a Las Vegas brothel where he had spent the last several days and rang up a tab of at least $75,000.

Workers at the Love Ranch have since told authorities they observed Odom taking cocaine and ingesting at least 10 herbal stimulant pills during his stay at the ranch.

On Friday, doctors reportedly told his family members that the improving performance of Odom's heart could go a long way in determining if he will survive his ordeal.

Word is doctors are also insisting upon calm in his room. They do not want Odom stimulated in any way, as non-stimulation promotes healing. With that mind, physicians have dramatically limited the number of people with access to his room.

Ex-wife Khloé Kardashian, who is rumored to be legally making all medical decisions for Odom, has not left his side since arriving at the hospital.

The New York-born Odom played 14 NBA seasons, winning back-to-back titles alongside Kobe Bryant and under Phil Jackson with the L.A. Lakers in 2009 and 2010.

Odom has a longtime history of drug and substance abuse, and recently, his childhood friends Bobby Heyward and Jamie Sangouthai both died of drug-related causes.