I had something like this occur once a few months ago. It was, I believe, a sort of GB attack. My blood pressure seemed to double (or worse) after I sat down in the bathroom, and my breathing rate increased dramatically, which only made me feel light-headed, further adding to my confusion over the situation.
But it mostly came and went, and I didn't give it much more thought (I think I posted about it earlier, though). It hasn't happened since, despite additional flushing, however.
So, to answer your question: no, it's not a typical GB attack.