Sunday, November 2, 2014

Increasing the Paper Speed in Narrow-Complex Tachycardia

Normal paper speed (25mm/s)
Authors: Destinee DeLemos, MD
Nathan Haas, MD
University of Michigan Department of Emergency Medicine

Narrow complex tachycardia often presents a diagnostic and therapeutic dilemma, and one simple trick can help in the correct identification of the underlying rhythm. With increasing heart rates, it becomes quite challenging for the emergency physician to distinguish between sinus tachycardia, paroxysmal supraventricular tachycardia (pSVT), atrial fibrillation and atrial flutter. If the underlying rhythm is not pSVT, an unnecessary adenosine trial can prove quite unpleasant for both the patient and physician.

Increased paper speed (50mm/s)
Images Courtesy of Amal Mattu, MD FAAEM

Standard 12-lead EKGs are printed at 25mm/second. By simply doubling the paper speed to 50mm/second, the printed rhythm strip appears widened and exaggerated, which can aid in identifying finer details of the EKG. The images in this post demonstrate previously hidden flutter waves becoming more apparent at an increased paper speed.

A 2002 study evaluated the impact of increased paper speed on emergency physicians' abilities to correctly identify and treat narrow-complex tachycardias.1 Correct diagnosis improved from 63% to 71% using this simple maneuver, and the incorrect use of adenosine was decreased from 18% to 13%. Before jumping to adenosine for a narrow-complex tachycardia, consider this quick and easy trick to help determine the correct rhythm and prevent your patient from experiencing an unnecessary "impending sense of doom."

  1. Accardi AJ, Miller R, Holmes JF. Enhanced Diagnosis of Narrow Complex Tachycardias with Increased Electrocardiograph Speed. The Journal of Emergency Medicine. 22.2(2002):123-26. Web. 14 July 2014.
  2. Lin M. Trick of the Trade: Speed up ECG Paper Rate to Differentiate Tachycardias. ALiEM. Academic Life in Emergency Medicine. 11 Dec. 2012. Web. 14 July 2014.
  3. Mattu A. Mattu ECG Case: Sept 11 2011. YouTube. N.p., 9 Apr. 2012. Web. 14 July 2014.

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