PBC's in heartbeat?

I've been under tremendous stress for months but in the past month I've had the "elephant on the chest" feeling with heartbeats I can feel that are sometimes almost painful and shortness of breath.  I'm in my mid 40's and 5 years ago I was hospitalized with chest pains.  The EKG was fine, the ECG showed some weakness of the heart muscle when it came to squeezing (their words) but I passed a treadmill stress test fine and still they did a (?)heart catheterization from the groin up on me.  Everything again came back fine.  I've experienced many times a rapid heartbeat, especially when at rest and told it was normal.  But due to my age, the stress and the fact that heart disease does run in my family I am concerned and did seek out my doctor.  Lab work came back good, EKG was good and today another ECG was run.  The tech asked if I could feel the irregular "extra" heartbeats my heart was throwing out and I can most times, even more so when stressed.  She called them PBC's which I had her repeat as I was assuming she meant PVC's but she said no- PBC's.  I can find no info. on them and under PVC's it says "missed or skipped beats" and that's not what I'm having, I'm having extra irregular heart beats.  What can you tell me about them?  And how worried should I be?  I go out of town in 2 weeks for a much needed vacation, is it safe to fly?  Thanks!  Gia

[itdood]

I don't think you're going to get much feedback on "PBCs".  I've never heard of them, tried a google search and no results came up for "PBCs and Heart".  Perhaps you should call your doctor to clear up the confusion and get clearance from he/she for flying.