Elsayed Z. Soliman, MD, MSc, MS; Prashant D. Bhave, MD; Lin Y. Chen, MD, MS
This Clinical Challenge reviews ways to distinguish atrial ectopy, AV block, multifocal atrial tachycardia, and other supraventricular tachycardias from atrial fibrillation in patients with absent P waves, irregularly irregular R-R intervals, and f waves on electrocardiography.