Cardiologist Cleveland Francis will practice a different kind of medicine Saturday by giving a benefit concert appropriately titled "Song of the Heart" for the American Heart Association at Arlington's Wakefield High School.

A Louisianian balladeer and longtime devotee of gospel and country music, Francis sees the link between medicine and music as the power to heal. "I had fears years ago that exposure as a musician would make my colleagues think I wasn't serious about my work . . . I was stunned when the exact opposite happened." With two previous concerts for Cardiac Rehabilitation for Mount Vernon Hospital netting more than $7,000, it is easy to understand why.

The concert, under the musical direction of Arthur Lisi, comusical arranger for NBC's "The Cosby Show," will cover the musical circuit with country, folk, light rock and contemporary gospel. The musical ensemble highlights Billy Pierce on lead guitar and the group Trumps. Making a special appearance are the Mount Calvery Baptist Church Gospel Choir and the Bel Pre Elementary School Chorus.

"It's pretty discouraging," says Francis, "to see a 38-year-old person dead from a heart attack. Unfortunately, a lot of our work is after the fact . . . treating people who have abused themselves for 40 and 50 years. By the time we get to them, it's usually too late." It's time, he says, to start educating America's youth about the fatal effects of cholesterol and smoking.