Frequent premature atrial contractions (PACs): when to worry?

[RegalPlatypus]

I'm 35, white, 6'-4" (193 cm), 155 lbs (70 kg). I've been having premature atrial contractions (PACs) for about ten years. These were originally diagnosed by wearing an event/Holter monitor. They've always been asymptomatic (i.e., no lightheadedness, fatigue, syncope, etc.). Because I'm very thin and have a minor case of pectus excavatum, I tend to feel the palpitations quite distinctly, though especially while inactive and sitting or laying down.

I have good days, sometimes stretches of days, in which I feel almost none. Then, without any discernible change in my behavior, I have bad days that may include periods of time with 3 to 4 PACs/min. I've had EKGs, a chest x-ray, cardiac MRI with and without contrast, and an echo. Structurally, my heart seems to be in good health.

Historically PACs were seen as a benign condition, but recent evidence is showing that frequent PACs are often predecessors of atrial fibrillation (AF) and yield higher risks of stroke and death. I've been on 2x daily 25 mg metoprolol for several months now with no effect on the frequency of my PACs. I'll soon be switching to Bystolic to give that a shot.

If beta blockers like Bystolic and metoprolol ultimately have no effect on the frequency of my PACs, should I discuss the possibility of catheter ablation with my cardiologist? Should I discuss Type III antiarrythmics? I'm sick of dealing with these palpitations and I don't want them to digress into a more serious type of arrhythmia.

[Occupant]

I have an RBBB and a very high Agatston score (1243) so I went to see a cardiologist. He did an Echocardiogram and gave me a Holter monitor. The Echo came out o.k., but the Holter showed 38,000 PACs per day. I am taking 50 mg of Metoprolol ER a day. That did not eliminate the PAC's, but I only have 22,000 per day now - so I keep on taking it.