The authors report the cases of 2 patients with symptoms and signs related to severe pulmonary hypertension. Two-dimensional echocardiography demonstrated defects in the posterior portion of the atrial septum. Transthoracic three-dimensional echocardiography clearly showed inferior sinus venosus atrial septal defects and their relationships with the inferior vena cava, the pulmonary vein, and the muscular border of the fossa ovalis. These 2 cases not only elucidate the potential value of transthoracic three-dimensional echocardiography in delineating the structural characteristics of unusual interatrial shunting but also remind clinicians to be aware of this potentially treatable cardiac defect during workup for pulmonary hypertension.
Case 1
A 35-year-old woman with a history of primary pulmonary hypertension was referred to our clinic because of progressive exercise intolerance. Transthoracic two-dimensional (2D) echocardiography revealed an interruption in the posteroinferior aspect of the atrial septum, but detailed anatomical localization was difficult ( Figure 1 A , Video 1 ). Color Doppler echocardiography showed a shunt through this defect ( Figure 1 B). Transthoracic three-dimensional (3D) echocardiography was performed (Philips iE33; Philips Medical Systems, Andover, MA) with an X-3 matrix-array transducer. Three-dimensional echocardiographic images cropped from the lateral aspect of the right atrium toward the atrial septum showed a large atrial septal defect (ASD) directly communicating with the orifice of the inferior vena cava (IVC); the muscular border of the fossa ovalis remained intact ( Figure 1 C, Video 2 ). An inferior sinus venosus ASD was diagnosed. Multidetector computed tomography showed similar findings ( Figures 1 D and 1 E). Right-heart catheterization revealed severe pulmonary hypertension (pulmonary arterial pressure, 86/45 mm Hg; mean pressure, 62 mm Hg; pulmonary vascular resistance, 19.2 Wood units). Inhalation with 100% oxygen for 10 minutes failed to decrease pulmonary arterial pressure significantly. The patient was treated with sildenafil and awaits heart-lung transplantation or lung transplantation with concomitant intracardiac repair.
Case 2
A 48-year-old man presented to his local hospital because of progressive dyspnea. A systolic murmur was heard during auscultation, and echocardiography showed a large, secundum-type ASD. He was referred to our hospital for attempted transcatheter closure of this defect. However, 2D and color Doppler echocardiography before cardiac catheterization showed that the ASD involved the posterior aspect of the atrial septum ( Figure 2 A ). Transthoracic 3D echocardiographic images confirmed the diagnosis of an inferior sinus venosus ASD; overriding of the atrial septum by the IVC was clearly demonstrated when viewed from the orifice of the IVC toward the roofs of atria ( Figures 2 B and 2 C, Videos 3 and 4 ). Furthermore, 3D echocardiographic images also showed overriding of the orifice of the right lower pulmonary vein across the atrial septum. Multidetector computed tomography confirmed the diagnosis of inferior sinus venosus ASD ( Figures 2 D and 2E); overriding of the right lower pulmonary vein across the atrial septum was also found ( Figures 2 E and 2F). Right heart catheterization revealed significant left-to-right shunt (Qp/Qs = 2.2) with ulmonary hypertension (pulmonary arterial pressure, 53/21 mm Hg; mean pressure, 37 mm Hg; pulmonary vascular resistance, 4.3 Wood units). Surgical repair of the ASD was recommended.
