Source:http://linkedlifedata.com/resource/umls/id/C1880480
NCI: A cardiac rhythm resulting from either an abnormal electrical focus in the atria or intra-atrial reentry. Atrial ectopic beats (AEB) refer to a contraction of the upper heart chamber which occurs before it would be expected. Atrial ectopic beats are also known as premature atrial beats, premature atrial complex (PAC), or atrial extrasystole.,NCI: A cardiac rhythm resulting from either an abnormal electrical focus in the atria or intra-atrial reentry. Atrial ectopic beats (AEB) refer to a contraction of the upper heart chamber which occurs before it would be expected. Atrial ectopic beats are also known as premature atrial beats, premature atrial complex (PAC), or atrial extrasystole. (NCI)