Gail Roper was fearful of making a scene.

Poised on the lip of a pool after swimming laps seven years ago, the former Olympic swimmer “knew something was wrong. It was like I was having an out-of-body experience. But it was scary.” She crawled out of the pool, rattled. A month later she experienced a second episode — her doctor later said her heart was beating irregularly. He suggested a pacemaker.