Complete Diagnosis by Transthoracic Echocardiography
A 56-year-old woman who underwent secundum atrial septal defect closure at the age of 25 years was referred to the Mayo Clinic for exertional dyspnea and symptomatic atrial fibrillation. On examination, she was acyanotic, with an irregularly irregular heart rate of 86 beats per minute and a blood pressure of 140/80 mm Hg. She had a fixed S2 split with a normal apical impulse.
During the course of her work-up, transthoracic echocardiography demonstrated anomalous pulmonary venous return of the right upper and lower pulmonary veins to the inferior vena cava just above the diaphragm (Scimitar syndrome). The right-sided chambers of the heart and pulmonary arteries were dilated because of left-to-right shunting. The left and right middle pulmonary veins entered the left atrium normally. The calculated pulmonary-to-systolic flow ratio was 2.5:1 (Figures 1 through 3⇓⇓ and Movies I through IV). Contrast-enhanced computed tomography scan and cardiac catheterization to delineate the anatomy of the vascular and bronchial anatomy also confirmed our findings and revealed a pulmonary arterial pressure of 46/31 mm Hg and pulmonary vascular resistance of 3.26 Woods unit · m2 (Figure 4 and Movies V through VII). The patient was referred for surgical correction.
When anomalous pulmonary venous drainage is suspected because of the characteristic radiographic curvilinear appearance of vein shaped like a “scimitar” or Turkish sword (scimitar sign) or increased caval flow into the right atrium, the diagnosis can be made easily by transthoracic echocardiography delineating the abnormal anatomy with the use of the “crab view” coupled with subcostal imaging to demonstrate anomalous pulmonary venous flow into the inferior vena cava below or just above the diaphragm.
The authors thank Mark Zangs for his expert technical assistance.
The online-only Data Supplement, which includes 7 movies, is available at http://circ.ahajournals.org/cgi/content/full/114/10/e373/DC1.