Nancy Guthrie's heart device may contain crucial evidence: ex-White House cardiologist

There's one key detail in Nancy Guthrie's abduction that could prove pivotal in finding her, an expert said on Wednesday.

Nancy Guthrie, 84, the mother of "Today" show co-host Savannah Guthrie, disappeared over the weekend from her home in Tucson, Arizona. Investigators have said they believe she was kidnapped from her home, although they have not yet released any information about potential suspects or persons of interest in the case.

Dr. Jonathan Reiner, a CNN medical analyst and former cardiologist in the White House, said during an interview on "Erin Burnett OutFront" on Wednesday that he is focusing on one detail as the case develops: Nancy Guthrie's pacemaker data.

Investigators have said they discovered Nancy's pacemaker was connected to her cellphone at around 2 a.m. on the night she disappeared.

Reiner said that the fact is important. It puts Nancy in close proximity to her cellphone at that time; the device could signal that it picked up an arrhythmia at that time, which could pinpoint when she was abducted.

"Above a certain heart rate, it would be possible that the pacemaker would detect that and then immediately upload that, you know, through its communication device," Reiner said. "We don't know whether this was just a routine check-in or whether it had detected an arrhythmia, but it's easy to know. All that needs to be done is to check with the implanting physician because that's where the data goes."