Wow, thanks for the play-by-play which sounds like a "typical" response ("No, really, I'm fine") and the classic pattern of symptoms -- chest pain, and pain in the left arm. Had you had non-classic symptoms (pain only in the upper back, as did one person I know who was having a massive heart attack), things may have turned out differently. It's very reassuring that your outcome is so positive.

The former president of our bike group died of a heart attack while riding apart from the group one morning. He was a most-beloved member, a strong rider for many years but always willing to ride in the back to encourage and support slower riders or anyone who needed mechanical support.

Earlier this year another member got off her bike, not feeling well, and turned down all offers for help from other group members. One of them offered to wait for her but she insisted against it. While she remained there alone, she blacked out and fell into the bushes. After that, she wore a monitor for a while and seems to be fine now, but we have a new group rule: "Leave no rider behind."

Based on these circumstances if I ever encounter a rider (or walker, runner, etc.) who appears to be in distress I will wait until help arrives.