Scimitar syndrome

Introduction: Partial anomalous pulmonary venous return (PAPVR) is a rare congenital anomaly found in 0.4%-0.7% of post-mortem examinations. In this entity, one or more pulmonary veins--usually from the right lung-lack left atrial connection. Connection of the right pulmonary veins to the right atrium or superior vena cava (SVC) is commonly accompanied by sinus venous atrial septal defect whereas connection of these veins to the suprahepatic inferior vena cava is usually part of the scimitar syndrome. We report an unusual case of bilateral PAPVR in whom the right and the left pulmonary venous anomalies were diagnosed and surgically corrected nine years apart.

Case Report: A 29-year-old black female, status post surgical repair of the right sided PAPVR and patent foramen ovale (PFO) nine years previously presented to the emergency room with sudden onset of shortness of breath, right-sided chest discomfort and palpitation. On examination, she was found to have a grade 2/6 systolic ejection murmur along the left sternal border and her electrocardiogram showed supraventricular tachycardia. 2-D echocardiography was performed that showed dilated right-sided cardiac chambers with normal left ventricular function. Calculated QP/QS ratio was 1.5:1, suggesting left-to-right shunting. Cardiac catheterization studies were performed. The oximetry and anglographic studies documented the presence of a sizeable anomalous left pulmonary vein draining into the left inominate vein with left-to-right shunt, calculated as 2.2:1 with high-normal to minimally elevated left ventricular filling pressure and pulmonary capillary wedge pressure and minimal pulmonary arterial hypertension. The anomalous left pulmonary venous connection was suggested by a transesophageal echocardiogram which showed absence of the left inferior pulmonary vein and a vertical venous structure connecting to the inominate vein. The latter connection was also documented by a CT scan of the chest. The patient underwent a successful surgical correction of the anomaly, reconnecting the anomalous left pulmonary vein to the left atrial cavity. The patient is now four years post-surgery and is doing well clinically.

Discussion: PAPVR in its commonest form involves the pulmonary veins from the upper or middle lobe of the right lung which connect to the right atrium or SVC instead of the left atrium. An atrial septal defect usually co-exists, especially the sinus venosus type and isolated PAPVR with intact atrial septum is exceptional. Anomalous connection of the left pulmonary veins is an extremely rare condition, occurring at a frequency of approximately one-tenth of the anomalous connections from the right lung. Bilateral PAPVR is quite rare. Our ease had a surgical correction of a partial anomalous pulmonary venous return and PFO nine years prior to her presentation for the second time. The diagnosis of the left-sided anomalous pulmonary venous connection was missed. Another cardiac catheterization performed eight years after the initial surgical correction suggested a local step-up at the high right atrial/low SVC level. However, the high SVC and left inominate blood [O.sub.2] saturations were reported as normal. The presence of the latter anomaly was suspected by careful blood sampling (see table below) and was subsequently established by the catheter manipulation into the anomalously connected veins and angiography. A CT scan of the chest with a diagnostic catheter left within the anomalous pulmonary vein, accurately identified its relation with neighboring structures, particularly the left atrium and greatly facilitated its surgical correction. The patient's baffle from the first operation was found to be functioning appropriately with no residual left-to-right shunting.

Conclusion: PAPVR is a rare congenital anomaly. This report documents an unusual case in which the right and the left pulmonary venous anomalies were diagnosed and successfully surgically corrected nine years apart.

COPYRIGHT 1999 American College of Chest Physicians
COPYRIGHT 2000 Gale Group