A regular feature of the American Journal of Critical Care, the ECG Puzzler addresses electrocardiogram (ECG) interpretation for clinical practice. To send an eLetter or to contribute to an online discussion about this article, visit www.ajcconline.org and click “Respond to This Article” on either the full-text or PDF view of the article. We welcome letters regarding this feature.Michele M. Pelter is an assistant professor at the Orvis School of Nursing, University of Nevada, Reno. Teri Kozik is supervisor of cardiac research at St. Joseph’s Medical Center, Stockton, California. Salah S. Al-Zaiti is a doctoral student at the School of Nursing at the State University of New York at Buffalo. Mary G. Carey is associate director for clinical nursing research, Strong Memorial Hospital, Rochester, New York.