Prolonged QT in a 13-Year-Old Patient with Down Syndrome and Complete Atrioventricular Canal Defect

[摘要] A 13-year-old girl with Down syndrome (Trisomy 21) was noted to have QTc prolongation on her 12-lead EKG. The patient was referred for further evaluation. The patient was born as a full-term baby at a local hospital. It was noted that she had a broad face, flattened nose, low set ears, microgenia, epicanthal folds, single transverse palmar crease, and unusual curving of the fingers. Her very first 12-lead EKG was performed at 13 days of age (Fig. 1) demonstrated normal sinus rhythm, right atrial enlargement, superior QRS axis, and right ventricular hypertrophy. Multiple subsequent 12-lead EKGs demonstrated evidence of QTc prolongation with nonspecific T wave changes and pronounced U waves (Fig. 2). This finding was thought to be secondary to her moderate mitral valve regurgitation with left ventricular enlargement.