My heart randomly stops beating for a few seconds at a time. I think I might go into cardiac arrest sometime. Doc gave EKG and said that it shouldn't affect me terribly. What do I do?

You go back to your doctor and ask him/her the questions you have. We don't know you or your medical history, but they do. Write down all the questions that you have so that when you have your appointment, you will have your questions ready. If you don't trust this doctor, find another one. It is your right to know what is going on with your body, however, they aren't mind readers. You need to go back to them with your health questions.

As Danae said, you need to go back to your doctor, or if you don't trust your current doctor, see someone else.  You need to tell them everything.

Keep a diary of when this happens including date, time, how long, symptoms, what you were doing at the time, and anything else that you think might be of interest to your doctor.  That way, the doctor knows what is going on, and what frequency and how bad it is with more detail and they are more likely and comfortable to give you a proper diagnosis earlier.

Get a second opinion, if symptoms are troubling you.

Some people have irregular heart beats but do not need medication for it, my mother has it.

Here's a link to heart arrhythmias it may or may not be useful:-

http://www.medicinenet.com/arrhythmia_irregular_heartbeat/article.htm

Both me & my mother have irregular heartbeats, which we have been told won't drastically affect us. It's probably genetic & it's probably not all that uncommon.