Electrical storm in an infant with short‐coupled variant of torsade de pointes

Figure 1. A, Defibrillation for ventricular fibrillation by automated external defibrillator. B, Torsade de pointes triggered by premature ventricular contraction with a short coupling interval of 240 ms. C, Twelve‐lead electrocardiographic recording at rest showing sinus bradycardia (heart rate = 83 beats per minute) due to deep sedation, a normal QT interval (QTc = 380 ms) calculated with Fridericia formula, with no sign of Brugada syndrome or early repolarization syndrome

Figure 2. A and B, Electrocardiogram recorded in implantable cardioverter defibrillator (ICD). Upper electrogram recordings were from the v‐sense/pace leads on right ventricle, and lower electrogram recordings were from epicardial coil lead for cardioversion and defibrillation on left ventricle to ICD can. A, Ventricular fibrillation, which was spontaneously restored to sinus rhythm. B, Defibrillation for ventricular tachycardia, which was triggered by premature ventricular contraction with a short coupling interval of 240 ms. The corrected QT interval before short‐long‐short sequence was not prolonged (QTc = 363 ms), which was calculated with Fridericia formula. C, Holter electrocardiogram recording before verapamil administration, showing isolated premature ventricular contractions with a short coupling interval (240 ms) and the nonsustained polymorphic ventricular tachycardia triggered by short‐coupled premature ventricular contraction at rest. Short‐long‐short sequences were not found in this electrogram