Telemetry is key for treating patients. Improper monitoring can lead to tragedy.

Telemetry is a critical tool in keeping patients alive, but without proper monitoring, it can lead to tragedy. A former executive with HCA, the nation’s largest hospital chain, described an “epidemic of telemetry mishaps” at some of its facilities. HCA says “telemetry saves lives and that is why we use it.” NBC News’ Cynthia McFadden reports.