Author: Anna Hartzog MD and Chinwe Unegbu MD – Children’s National Hospital


A 9-month-old male with Hypoplastic Left Heart Syndrome who has undergone Stage I repair with the Norwood procedure and a modified Blalock Taussig shunt followed by a bidirectional Glenn procedure presents for routine cardiology follow-up. Which of the following echocardiographic findings has the GREATEST PROBABILTY to increase mortality in this patient?