Welcome to HCM!
I have gone through your question carefully and from that it looks like that you are otherwise a healthy adult, work out regularly and do not have any other stress/ anxiety
. Now there has been an episode in which your heart was pounding hard, slowing down, there was a tingling
rush all over the body and lasted for 30 seconds or so.
I think you should see a doctor, had I been treating you I would go for an ECG and blood pressure, blood sugar levels etc.,checked.
Only after this one can say what had happened. This thing should not be ignored.
Please see a doctor atleast once .
Hope this reply helps you out
Please ask if you have more queries related to it.
Dr. Manisha Gopal.