He says: "We were on tour somewhere and the stage temperature goes up by about 100 with all the stage lights. My heart would go, 'Ba boom, ba boom.' I started perspiring, getting dizzy and short of breath.

"I called the doctor, who said, 'This is what's going on. This is something called A-Fib,' and he went through a list. It was a lot to take in." But Simmons says that, while he is prone to symptoms, he gets enough sleep and drinks a lot of fluid to prevent another scare.