My 34-year-old son recently fainted -- not his first time, it has happened every so many years -- but it was concerning because he was just walking down a sidewalk, no triggers/warnings, was lucky he didn't mess up his face/head too badly (but he did some) or get hit by a car. He then lost consciousness twice in the ER where his heart stopped for 30-50 seconds each time, including once was while asleep. After a battery of heart tests, he's still diagnosed with vasovagal syncope and nothing more. Anyone have similarly alarming circumstances? Any luck avoiding a repeat?