I've Had PVC's In The Past 20 Years And Tachycardia.

I've had PVC's in the past 20 years and tachycardia. am on Lopressor. had an episode last week of a long period of fluttering and light-headedness lasting maybe 8-10 seconds (ears ringing and feeling of hotness in the pit of my stomach). then everything returned to normal. I also suffer from panic disorder and am on Paxil. This episode happened once last year while I was driving. What is going on? Been checked out by a cardiologist 20 yrs ago. He released me saying it was just PVC's.