Glad your results were good. The only way to describe ectopic heartbeat is
"Any heartbeat that occurs out of the normal sinus rhythm (which is normal rhythm) of the heart. Premature beats can be exacerbated by the use of stimulants such as caffeine, smoking, alcohol, and also decongestants".
I am not medically trained but thought this the best straightforward way to explain it. I am particularly interested in anything connected with the heart as I have had two heart attacks and a triple bypass.
The only thing though if you aren't satisfied with anything at all that your doctor says, you must ask and ask to put your mind at rest.
Hope you're doing ok.