I'm referring to patterns such as bigeminy, or if they occur in groups such as couplets or triplets. Most of the articles I found online about "bigeminy" refer only to ventricular bigeminy. As for couplets and triplets, I was not able to find any reliable articles or websites mentioning "atrial couplets" or "atrial triplets". The only site I was able to find is a suspicious foreign online doctor site written in broken English. It seems like atrial ectopic beats are almost always isolated. Does anybody know if this is indeed true, and if so, what prevents atrial ectopic beats from occurring in pairs, triples or in a bigeminy pattern?
Also, I am aware that supraventricular tachycardia lasts for at least a couple of minutes, unless terminated by a Valsalva's maneuver or by administration of drugs. I was not able to find any supraventricular analogue of NSVT.