Torsades de Pointes is an extremely rare arrhythmia in children associated to LQT syndrome. Pheochromocytomas are also extremely rare tumours in the paediatric age. We present a case of a young patient with an acquired long QT syndrome complicating with Torsades de Pointes as first clinical manifestation of a pheochromocytoma.

We report a case of 2:1 atrioventricular block associated with acquired long QT syndrome. A newborn presented to our neonatal intensive care unit with intermittent bradycardia due to 2:1 atrioventricular block. Initial evaluation showed QT prolongation and significant electrolytic abnormalities. After correction of the electrolytic imbalance, the QT interval normalized and atrioventricular block resolved. Compared to congenital long QT syndrome with 2:1 atrioventricular block, acquired long QT syndrome with comparable atrioventricular block has a benign prognosis, provided treatment is initiated quickly.

Acquired lengthening of the QT interval due to hypocalcaemia is a rare cause of arrhythmia in childhood. Early recognition, rapid institution of appropriate cardiac monitoring, and replacement therapy are essential. An endocrinal work-up may be necessary to exclude primary disorders of calcium metabolism. We report four cases documenting the varied clinical spectrum in which hypocalcaemic-induced prolongation of the QT interval and arrhythmia can occur in childhood.