What helps with an irregular heartbeat? What foods should I eat, and what foods should I stay away from?

Tea, Cocoa, Coca cola, mountain dew and others ( check labels) aged cheeses, foods containing msg, alcohol , stress, lack of sleep all contribute to ventricular premature contractions.

Causes of ectopic beats or rhythms food wise would be those that would disrupt one's magnesium, electrolyte, and calcium balance. Not having adequate levels can contribute to various forms of these irregular beats/rhythms. As you said, caffeine should be used in moderation as well as other high sugary and salty beverages. Foods high in sodium also should be something to be eaten in moderation.