Speaking from experience Rick! Had the odd one or two, then drank a ridiculous amount of coffee one day, went for a run on a stressful day the next and had palpitation for a week, fixed eventually by beta blockers. While I had it they put me on aspirin with the plan being to go to blood thinners to reduce stroke risk. Once it went away docs were happy to stop the meds and not seen it since - I drink less coffee too (but still some).
Glad to hear you stopped. You'd have probably struggled anyway as you have less puff during palpitations.
They are surprisingly common, once I mentioned I'd had one lots of others said they had too.
If chest flutter is the same as heart palpitation (e.g. atrial fibrillation), it's a bad idea to run though it. Whilst your heart is beating irregularly you're at a much higher risk of stroke, so making it work harder is likely to be bad. Most likely it will recover of its own accord if you stop for a few minutes and you can then carry on running. If not, GP/cardiologist is needed to sort it out.