Complete Atrio-Ventricular Septal Defect and Wolf-Parkinson-White Syndrome

A full term female infant was born after 41 weeks of gestation, with a birth weight of 3815g and normal Apgar scores (9-10- 10). Immediately after birth tachycardia was noted. An electrocardiogram (ECG) showed a heart rate of 300 beats per minute (bpm) and narrow QRS complexes. The newborn was clinically stable. She was admitted to the neonatal intensive care unit and an intravenous line was inserted for treatment with Adenosine. While preparing for Adenosine infusion her heart rate spontaneously decreased. Her ECG at presentation with normal heart rate is shown in figure1a. On auscultation, a soft systolic murmur was heard. Echocardiography was performed and demonstrated a complete atrio-ventricular septal defect (AVSD) with a large primum defect, large ventricular septal defect, common atrio-ventricular orifice (AV-valve), and balanced size of the right and left ventricles. At around two hours of age the infant started to get frequent, short episodes of supraventricular tachycardia alternating with sinuous rhythm (figure 1b). Prophylactic treatment against recurrent tachy-arrythmia with Digoxin was started (full digitalisation within the first 24 hours and then with a maintenance dose of 5 ?g/kg, B.I.D). The infant was observed for several days and continued to be free of symptoms. She was discharged to her home at five days of age. She was seen five days later and was found to be clinically stable with no tachy-arrhythmia. Her ECG then is shown in figure 2.