A 47-year-old Edgewater man died shortly after 6 a.m. yesterday after an apparent heart attack while driving a pickup truck in Davidsonville, county police said.

Roger Dale Altizer of the 1700 block of Shore Drive was pronounced dead on arrival at Anne Arundel Medical Center, police said.

Witnesses reported seeing Mr. Altizer's 1985 Ford truck heading west on Route 214, just west of Riva Road. The truck then left the roadway, went into a ditch and scraped a tree. Witnesses told police it appeared the driver tried to pull off to the shoulder, but could not stop the truck.

Police are waiting for an autopsy report to determine whether Mr. Altizer died from a heart attack or his injuries.