Efficacy and safety of cardioversion with continuous landiolol infusion for atrial tachyarrhythmia in an inflammatory state caused by volvulus in a child with TARP syndrome and postoperative tetralogy of Fallot

A 2-year-old boy was diagnosed with TARP syndrome and underwent surgery for tetralogy of Fallot. He developed fever and had an acute abdomen. After 12 hours, atrial tachyarrhythmia (300 beats/min [bpm]) occurred. After nine administration of adenosine and two cardioversions, it relapsed promptly. Landiolol (10 μg/kg/min) was administered until the heart rate decreased to 270 bpm, and cardioversion was performed until sinus rhythm was normal. Exploratory laparotomy revealed small bowel volvulus. Systemic inflammation causing an acute abdomen may be associated with atrial tachyarrhythmia in postoperative tetralogy of Fallot. We speculated that landiolol lowered the defibrillation threshold of the atrium.