Unconfirmed media reports say Nancy Guthrie's pacemaker stopped syncing with her Apple devices. Here's what that means.

Nancy Guthrie’s 2 a.m. pacemaker spike on the day she vanished could mean that the elderly woman was involved in a heart rate-surging struggle with her possible captors, a lead cardiologist speculated Thursday.

Cybersecurity expert Morgan Wright analyzes Nancy Guthrie's abduction and highlights a 41-minute window between the doorbell camera and her pacemaker app disconnecting on ‘America Reports.’

Pima County Sheriff Chris Nanos provided the public with updates on Tuesday, February 3, regarding the disappearance of Savannah Guthrie’s mom, Nancy Guthrie, including the report that her pacemaker had stopped syncing with her Apple devices.

Nancy Guthrie’s pacemaker reportedly stopped syncing with her Apple devices predawn Sunday morning – as the Arizona sheriff leading the missing person case called a surprise press conference for late Tuesday morning.

A man who had a pacemaker fitted when he was just nine years old has gone on to complete two marathons. Kieran Cooper, of Blackpool, Lancashire, was born with a heart condition and was never allowed to play sports as a child. He said he found this incredibly difficult but "thankfully there is a different mindset nowadays".

Fox News' John Roberts, who has a pacemaker, detailed it's bluetooth capabilities and how it may relate to the search for missing Nancy Guthrie. (Credit: Fox News)

In most families a phone is the first thing looked at once someone has vanished; in other cases, a heart device software creptily takes the place of a clock. The case of Nancy Guthrie, 84, sought has demonstrated the role of contemporary investigations by relying on two rather contrasting types of evidence: upsetting messages that