Case Presentation:
A 5 month old female presented with a 3 day of history of nasal congestion, cough, and worsening respiratory status. Her past medical history was significant for three prior respiratory illnesses, one of which required hospitalization. In the emergency department, her vital signs were T 39.1°C, HR 174 beats/min, RR 68/min, BP 102/62 mmHg, and Sp02 97%, dropping to 88% while asleep, and weight 4.8kg (<3%ile). Examination revealed a small infant in moderate respiratory distress with subcostal and suprasternal retractions. Lungs revealed diffuse rhonchi but no wheeze. The remainder of her physical exam was normal. Chest x‐ray (CXR) demonstrated right basilar airspace disease, a trace right pleural effusion, normal pulmonary vasculature, and the heart was normal in size but was slightly displaced to the right (Fig 1). Rapid RSV antigen was positive. CBC was significant only for an elevated WBC at 18.5 x103/μL (52% neutrophils, 34% lymphocytes). She was admitted for supportive care due to RSV bronchiolitis and for IV ampicillin for possible secondary bacterial pneumonia. It was also noted that she had failure to thrive (FTT). Due to worsening respiratory distress a chest ultrasound was obtained that demonstrated a small pleural effusion and a small pericardial effusion. Cardiology was consulted and a transthoracic echocardiogram revealed abnormal pulmonary venous drainage consistent with the diagnosis of Scimitar syndrome. Retrospective review of the original CXR demonstrated the classic Scimitar sign parallel to the right cardiac border (Fig 2).
Discussion:
RSV bronchiolitis with respiratory distress is frequently encountered by pediatric hospitalists. Respiratory distress in conjunction with poor growth and a history of recurrent respiratory illnesses should prompt clinicians to consider other etiologies such as congenital heart disease. Scimitar syndrome is a congenital cardiovascular defect consisting of a hypoplastic right pulmonary artery and right lung, anomalous systemic arterial supply to the right lung, and a curved anomalous right pulmonary vein that drains into the inferior vena cava. Clinical presentation can be variable, ranging from infants who are asymptomatic to infants with respiratory distress, cyanosis, poor growth (due to a physiologic left to right shunt though an ASD), heart failure and severe pulmonary arterial hypertension. CXR often demonstrates the “scimitar” sign which is pathognomonic for Scimitar syndrome; however it is often hidden by the cardiac shadow. Diagnosis is confirmed by echocardiogram. Treatment consists of monitoring for worsening pulmonary hypertension, and lasix is often used as adjunctive therapy. Surgical correction is the only available treatment for severe disease.
Conclusions:
In infants with respiratory distress and FTT, even in the setting of classic bronchiolitis, a possible underlying cardiac etiology should always be considered.
