Are you 100% sure that it was positive stress that got you into the ER? I myself distinguish between stress (=anxiety of not meeting goals in time), and positive motivation (=joy, and not the caffeine one). Sadly, I haven't had much of the second type in recent years, but it's something I'm working on. It sounds as if your HPA axis gets super worked up and your body enters fight or flight mode, causing your heart to go crazy. That's what kept happening to me until I actively took care of the underlying stresses or beliefs I have while coding ("I'm not gonna make it" / "I won't have the time to finish it" / "I won't finish this task today but I desperately want to"...). I didn't get heart symptoms, but rather fatigue and anhedonia.
Just some thoughts on caffeine, since I think stress in programmers is often caused by it, or covered up:
I only very rarely have caffeine, and rather do vitamins if I need to be more stress resistant (Vit C, D, K2, Pantethine and sometimes B vitamins). That way I'm not fooled by the motivation that comes with caffeine, which somehow covers up what I really want to do. If I have caffeine I get giddy about the thought of writing this and that tool, while I couldn't care less when off caffeine.
It's hard to describe, but I can quite easily get "into the flow". This is where I focus on a single project, time cease to exist and I just become one with the code. I can focus on coding for hours and hours without break. In fact, lunch and toilet breaks are irritating distractions. I can go to sleep at night uneasy about something I'm not exactly sure about and suddenly the solution strikes me when I'm half awake in the shower next morning.
I don't use much caffeine, a bit of coffee in the morning, rarely in the afternoon – however I do know that coffee and alcohol makes my condition worse.
It's totally engulfing and extremely productive. This _is_ the mythical man month that people talk about. Only. For me it takes a toll. It's not about any underlying stress like "I won't make it in time". My work is luckily such that I don't have much pressure. It's being "in the zone" that is the problem.
The "flow state". I love it yet mustn't overdo it.
I don't think you need to label this as a condition. I can remember when I used to get into those states. Sadly, it was an artifact of my youth.
I probably would be able to get back into that state if I somehow managed to get all my responsibilities squared away for large periods of time-or alternately, convince myself thoroughly enough to ignore them.
Just some thoughts on caffeine, since I think stress in programmers is often caused by it, or covered up: I only very rarely have caffeine, and rather do vitamins if I need to be more stress resistant (Vit C, D, K2, Pantethine and sometimes B vitamins). That way I'm not fooled by the motivation that comes with caffeine, which somehow covers up what I really want to do. If I have caffeine I get giddy about the thought of writing this and that tool, while I couldn't care less when off caffeine.