Late Presentation of a Rare Congenital Cardiopulmonary Defect: Scimitar Syndrome

Abstract

INTRODUCTION: Scimitar syndrome (SS) is a rare congenital disease. It is characterized by abnormal drainage of right pulmonary vein into inferior vena cava or right atrium instead of left atrium. It is commonly associated with hypoplastic right lung and right pulmonary artery as well as dextroposition of the heart. The name of the syndrome is derived from the radiographic manifestation of the anomalous vein resembling a Turkish sword. CASE PRESENTATION:A 45 years old woman with history of obstructive sleep apnea, hypertension, morbid obesity, recurrent mild respiratory infections since childhood. She complained of cough and dyspnea on exertion for four months. Over that period, she was repeatedly treated with several courses of antibiotics and steroids. During this period, she also gained 40 pounds. With progression of shortness of breath and need for supplemental oxygen, she was referred to pulmonology clinic. Chest CT with contrast reported hypoplastic right lung with a prominent right pulmonary vein draining into the junction of inferior vena cava and right atrium, compatible with Scimitar Syndrome. On further workup, PFT showed moderate restrictive pattern, echocardiogram showed evidence of mild pulmonary hypertension. She was then referred to a tertiary center and eventually underwent surgical anastomosis of the Scimitar vein via the present atrial septal defect into the left atrium, with patch enlargement of the ostium of the scimitar vein at its entrance, and tricuspid valve repair commissuroplasty. After surgery, her dyspnea improved significantly from having dyspnea at rest to having dyspnea only with moderate activity. supplemental oxygen was weaned to continuous 2 liters of nasal canula. She continues to improve with cardiopulmonary rehabilitation and has recently returned to work. DISCUSSION: SS accounts for 0.5-1 percent of all congenital heart disease cases. The prevalence of SS is estimated to be 1-3 of every 100,00 livebirths. Two types of SS have been described, the infantile and adult forms. Infantile form is usually associated with other thoracic and vascular abnormalities. Adult form has a smaller shunt and is more commonly isolated. Atrial septal defect is the most common associated cardiac anomaly in both adult and infantile forms. Echocardiogram with color doppler studies as well as computed tomography are the mainstay diagnostic tools. Most patients are asymptomatic at birth. Clinical symptoms are similar to ASD. Exercise intolerance is the most common complaint. Depending on the shunt volume, patients may range from completely asymptomatic to having dyspnea and recurrent respiratory infections.CONCLUSIONS: Scimitar syndrome is rarely seen in adulthood and can present as a progressive disease. Many types of surgical repair have been proposed. Most repairs are designed to divert the anomalous connection between pulmonary veins and systemic veins and drain the flow to left atrium.