No. If you had a heart attack and didn't get medical treatment, you'd be dead right now.
But that's not to say it's nothing serious. If I had to guess I'd say your heart had a misfire that made it malfunction for a short while. I'd suggest talking to your doctor about hereditary heart conditions, since on sunday I took in about a gram of caffeine (DON'T repeat) over about an hour and apart from the crash, I was totally fine, which suggests your heart is vulnerable to disruptions, and you need to get that checked out before you do have a heart attack.