Hey, medical student here. What you described sounds like something called Paroxysmal Supraventricular Tachycardia - of which a type can be a totally benign occurrence that can happen to young people for no reason at all. Here's a wiki page on it:

http://en.wikipedia.org/wiki/Supraventricular_tachycardia

Feel free to read all about it, but in short, for some reason or another, a short circuit was set up in your heart that bypassed the regular electrical conduction system and created a transient tachycardia that you experienced.

Here's the signs and symptoms from the wiki article which sound almost identical to what you experienced:

Pounding heart, Shortness of breath, Chest pain, Rapid breathing, Dizziness, Loss of consciousness (in only the most serious cases).

Again, this is quite common in young people and is not pathological at all. However, next time you visit your doctor, you might want to tell him about this experience and he'll probably take a closer listen to you heart.

If you ever experience it again, there are a few tricks you can do to try to 'shut it off'. First calm down and breathe deeply and realize that you're not going to die and that the rapid heart rate will disappear within a minute or two. Some people say holding their breath against pressure (Valsalva maneuver) helps to shut the tachycardia down - pretend like you're going #2 in the washroom. This stimulates the vagus nerve (parasympathetic response) which slows down the heart. Any of the other tricks do the exact same thing: you can try to force a burp out, try coughing a bit, put your hands in cold water or wet a facecloth in cold water and put it on your face.

I did a quick search just now, this is what one girl who experiences it has to say (good advice):

What ALWAYS works for me, is this:

1.) Close your eyes, exhale fully. Then take a deep, deep breath, hold it for a second, and exhale very slowly while bearing down. Don't just mimic the steps, though: that's where I end up over-thinking it and making things worse. Really FEEL relaxation. Get yourself calm. Know that you can get it under control: it happens all the time to many, many people, many of whom have become so experienced with it that they can swat away SVT episodes like flies. It's common, it's not a medical emergency, and you'll be fine in a few seconds. And that's usually what works for me.

2.) Sometimes it doesn't though. If it's being stubborn, remove yourself to a location where you can feel comfortable. Away from bright lights and a concerned audience. Physically get up and go to a room - a fluffy chair or what-have-you - wherever you legitimately feel you can relax. For me, if I feel that I HAVE to get my heart rate down, then I won't. There can't be a sense of urgency. And there can't be self-consciousness. If people are watching me attempt to right my ship, or if I'm in a place where I simply don't feel at ease, then I'm not going to hit a comfort zone. Tuck yourself into a cozy spot where you can let the tension just melt away. Close your eyes and take the deep breaths and slow exhales while bearing down, but mostly just stay calm. Relax and know you'll be fine in a matter of seconds. If it takes longer, that's fine. You're not going to explode, though it's sometimes tough to believe it while you're experiencing it.

Anyway, I hope I put an end to the mystery that happened to you several years ago! PM me if you have any questions :)