A 7-month-old girl weighing 5.3 kg, presented with atrial septal defect (ASD) and paroximal supraventricular tachycardia (PSVT). The preoperative electrophysiological study could not be performed because of the severe heart failure. On suspicion of a concealed Wolff-Parkinson-White (WPW) syndrome, whose accessory pathways conduct in the retrograde direction… (More)