Hard to say, probably not but if you are worried you could always see a heart doctor (cardiologist) or internist for some further tests?
I see you take some beta blockers (propranolol) and if you have an on-and-off-effect from those, you could possibly ask your doctor about a slow-release variant of the drug where you take one pill with a 24 hour duration? They are available with the name Inderal Retard (funny name by the way).
If you recently got your panic attacks back, something is obviously stressing you and usually this is the same stress as are to blame for your arrhythmias. Remember, panic attacks are not coming out of the blue, they are a sign of underlying stress that sometimes tips over the edge.
Maybe you should think about what is causing your stress? In my case, it was moving together with my girlfriend (which wasn't a bad thing but it was the first time I had to live a life where I wasn't completely in charge and had to adjust my lifestyle). Your symptoms are just like mine.
I often get symptoms not during, but after a stressful day, etc. After dinner and before sleep are "main triggers". Maybe you should see a cardiologist but be careful not to relate this too much to your heart. Usually the heart is not to blame but the problems express themselves through that organ.
Did you feel your heart skipping beats while they did the ekg? If so then the skipping feeling could just be your heart beating a bit fast. Either way if it was skipping when they did the ekg and they told you that you were fine then I don't think you have much to worry about. If however, it wasn't skipping you may need to have a follow up with your doctor to get a monitor to catch the skipping beats. Once the doctor is able to see the issue he will then work with you on next steps. It is likely though the skipped beats will be of no consequences. A lot of people have them and live long lives. And unless you have over 20,000 in a day or a lot of them in a row they really don't do much for them. It is up to us to try to avoid the things that trigger them and do our best to deal with the stress in our lives so we can better handle the missed beats. Stress will definitely make your heart feel worse. So I really don't think you have anything to worry about but you really should consult your doctor to get a firm diagnosis on what you are dealing with. Good luck and hang in there. There are many here how have much the same problem as you and we are managing just fine.