The bad news: Not that it's really bad, but there's no known reason yet why the rate of occurrence of this has increased the way it has.
Thankfully my doctor figures that this heart thingy is rather important, so we're doing a bunch of tests, including the equivalent of a 24hr flight recorder. Once all the results are in, it's off to cardiology.
I'm still hoping this all just goes away, which would be rather indicative of the wealth of stress I put myself under on a continual basis. That needs to be addressed as well.
I still get to exercise, just not full-on high-intensity. There's no formal guidelines here, just the thought of "take it a bit easy for a while." No worries there. :D