William J. Castillo, MD

A 2-year-old girl was seen by her pediatrician because of a 3-day history of runny nose, cough, congestion, and low-grade fevers. A viral upper respiratory tract infection was diagnosed and supportive care was recommended. The child returned 2 days later with persistent cough, mild tachypnea, and an episode of vomiting. The cough and tachypnea prompted the pediatrician to order a chest film, which revealed an enlarged cardiac silhouette.