I've had panic attacks solely from physical causes - Prozac. I knew what they were, had an idea what was causing them and just rode them out.

I've had them because of stress, and those seem a bit easier to turn off. I've had just a little bit of traning on meditation, and getting my mind to shut up and stop that manic gibbering 'voice' works. The likelihood that it will come back is greatly diminished if I can find something to do that requires a sort of semi-mindless concentration: gardening, cleaning stuff, beadwork. Deep breathing helps, and some physical exercise actually makes my heart slow down.

The best thing is to determine, along with your doc, what starts these and do something about that. It's so much better to prevent the symptoms than deal with them after they occur,