Atrial ectopic tachycardia. Notice regular narrow QRS Atrial ectopic tachycardia. Notice regular narrow QRS. P waves originate from an ectopic atrial focus and not the sinus node. Source: Treatment of Arrhythmias During Pregnancy, Maternal Medicine Citation: Pacheco LD, Saade GR, Hankins GV. Maternal Medicine; 2015 Available at: http://obgyn.mhmedical.com/DownloadImage.aspx?image=/data/books/1580/pac_ch7_f004.png&sec=96349474&BookID=1580&ChapterSecID=96349452&imagename= Accessed: December 30, 2017 Copyright © 2017 McGraw-Hill Education. All rights reserved