Thank you that helped a lot!
I've had Premature Ventricular Contractions (PVCs) and Premature Atrial Contractions (PACs) on and off, over the years, for nearly 40 years.
For this reason, I can't:
Smoke, drink alcohol, consume drinks or foods with caffeine (i.e. no coffee or chocolate), take certain cold medications or recreational drugs, drink or eat energy drinks or bars, go without sleep, and a bunch of other things. Sure, my doctor says my problems are benign, but I dislike the rhythm disturbances more than I like the things I listed.
I would suggest you avoid those substances as well. The following sites helped calm me a lot about premature beats, give them a look over.
http://www.drjohnm.org/2013/06/benign-pvcs-a-heart-rhythm-doctors-approach/
http://www.aafp.org/afp/2005/0215/p743.html
Did the doctor identify what you are feeling on the Holter or EKG?
It's very common for people to have premature beats, most are unaware that they're having them. I'd keep in touch with your doctor if you have new symptoms. If they have not captured your symptoms on a monitor, a longer session with a Holter or an event monitor may be an option.