Echocardiographic clues and accuracy in the diagnosis of scimitar syndrome.

Scimitar syndrome was diagnosed in 27 patients seen between July 1974 and May 1993. All available echocardiograms taken before surgery or death were reviewed. Age at presentation ranged from 1 day to 14 years. Dextrocardia or mesocardia was noted in 70%, atrial septal defect in 70%, and increased right ventricular dimension in 70% of the patients. The ratio of the proximal and distal diameters of the right/left pulmonary arteries were reduced 0.68 +/- 0.17 and 0.66 +/- 0.17, respectively. "Blunting" of the right side of the left atrium was seen in all patients with total anomalous right pulmonary venous drainage and none with partial drainage. Anomalous right pulmonary venous drainage was characterized in 91% of echocardiograms with color flow mapping versus 14% without color flow mapping (p < 0.0002). Aortopulmonary collateral arteries were detected in all four cases in which color flow mapping was performed, but not detected otherwise.