Example of T wave alternans from a 3-year-old patient with long QT syndrome with multiple episodes of cardiac arrest. Tracings are from a 24-hour Holter recording.
ECG: electrocardiogram.
Reproduced from: Schwartz PJ, Crotti L. Long QT and short QT syndromes. In: Cardiac Electrophysiology: From Cell to Bedside, 6th ed, Zipes DP, Jalife J (Eds), Saunders, Philadelphia 2014. Illustration used with the permission of Elsevier Inc. All rights reserved.