I have been having episodic PVC's for years, but lately they have become chronic and can interfere with falling asleep or will wake me. My cardiologist prescribed Bystolic 5 mg., but on their web site, they caution people with "irregular heartbeats" not to take it. I called the 800 number they listed, but they couldn't tell me why. It seems to me that if they caution me not to take it, that I shouldn't. Now what?