Welcome to HCM
We understand your concerns
I went through your problem descriptions. I suggest you not to worry any more about the episode happened because sincerely there is nothing to worry. The episode had not returned after that, right?
You were erecting a tent before that episode. May be you got over tired and lethargic. Fast heart beat suggests adrenaline
rise, then you might be fearing about what might happen. There are so many leading guiding pointing marks. Better to ignore them till next episode happens, because if you start your check up now, it might mislead you and your doctors.
Just make sure you don't worry about past. Hope this answers your question. Available for further clarifications.