Retired New Hampshire State Trooper James “Chris” Decker believed his back pain signaled an injured disk — a suspect he had been warned to watch.

Decker, then 50 — fit, healthy, and an active outdoorsman — never considered it could be coronary artery disease, let alone a medical emergency that would test the boundaries of life and death.

John "Chris" Decker

Retired New Hampshire state trooper John “Chris” Decker, in his Epsom home, holds a sample of the heart pump that saved his life.

At the summit

John “Chris” Decker stands atop Mount Washington with his daughter, Jayla, in this undated photo.

Hurricane relief team

John “Chris” Decker, center, in uniform, gathers with the Mass General Hospital disaster relief team gather in Puerto Rico, where they were helping with hurricane relief efforts in 2017.