The 78-year-old rock 'n' roll pioneer was listed in stable condition at a Florida hospital Tuesday after suffering a heart attack, according to his publicist, Susan Clary.

Diddley reportedly complained of dizziness and nausea Friday during a routine medical checkup and was taken to North Florida Regional Medical Center in Gainsville, near his hometown of Archer.

He is currently in the cardiac care unit, after spending the weekend in intensive care, Clary said.

"He is conscious," Clary said. "The situation is very serious."

The singer-guitarist was previously hospitalized in Nebraska in May after suffering a stroke following a string of casino performances in Council Bluffs, Iowa.

He was later transferred to Florida to continue his recovery.

Considered one of the founders of rock 'n' roll, Diddley's eponymous beat drove such classics as "Bo Diddley," "Say Man" and "Who Do You Love?" and influenced generations of rockers, including Buddy Holly, the Rolling Stones, U2 and the Clash.

He was inducted into the Rock and Roll Hall of Fame in 1987 and received a Grammy Lifetime Achievement Award in 1998.