Jerry Lewis, the entertainer with a mighty heart, died because his heart gave out, according to the death certificate signed by his doctor after the comedian died Sunday at his home in Las Vegas.

Clark County Coroner John Fudenberg confirmed to USA TODAY Monday that Lewis' death was natural.

Fudenberg said Lewis' attending physician signed the death certificate, listing his official cause of death as end-stage cardiac disease due to peripheral vascular disease. In layman's terms, Lewis' heart became progressively weaker and eventually stopped working.

Because Lewis died under the care of a doctor, an autopsy will not be performed, Fudenberg said. Lewis was 91 when he died, surrounded by his family.

Lewis was one of America's most popular entertainers ever — a consummate showman, comedian, director and actor with a decades-long career.

But he became just as beloved for his enduring devotion to “Jerry’s Kids,” the children affected by muscular dystrophy.

He used his worldwide fame to raise awareness of the degenerative disease and more than $2 billion to fight it, most notably through The Jerry Lewis MDA Telethon, which he hosted from 1966 to 2010.

His death brought forth a rush of tributes from fellow comedians, celebrity fans and countless others who benefited from his philanthropy.