Diagnosis of Inferior Sinus Venosus Atrial Septal Defects Using Transthoracic Three-Dimensional Echocardiography Chun-An Chen, MD, Jou-Kou Wang, MD, PhD, Jui-Yu Hsu, MD, Hsao-Hsun Hsu, MD, Shyh-Jye Chen, MD, PhD, and Mei-Hwan Wu, MD, PhD
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. (J Am Soc Echocardiogr 2009;23:457.e4-e6.) Keywords: Sinus venosus atrial septal defect, Pulmonary hypertension, Three-dimensional echocardiography
CASE 1
CASE 2
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 1A, Video 1). Color Doppler echocardiography showed a shunt through this defect (Figure 1B). 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 1C, Video 2). An inferior sinus venosus ASD was diagnosed. Multidetector computed tomography showed similar findings (Figures 1D and 1E). 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.
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 2A). 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 2B and 2C, 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 2D and 2E); overriding of the right lower pulmonary vein across the atrial septum was also found (Figures 2E 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.
DISCUSSION From the Departments of Pediatrics (C.-A.C., J.-K.W., M.-H.W.), Surgery (H.-H.H.), and Medical Imaging (S.-J.C.), National Taiwan University Hospital, Taipei, Taiwan; and the Department of Pediatrics, Buddhist Tzu-Chi General Hospital, Taipei Branch, Taipei, Taiwan (J.-Y.H.) Reprint requests: Chun-An Chen, MD, Division of Pediatric Cardiology, Department of Pediatrics, National Taiwan University Hospital, No 7, Chung-Shan South Road, Taipei 100, Taiwan (E-mail:
[email protected]). 0894-7317/$36.00 Copyright 2009 by the American Society of Echocardiography. doi:10.1016/j.echo.2009.09.008
Sinus venosus ASD accounts for only 10% of ASDs and is commonly associated with partial anomalous pulmonary venous return.1 The defect is posterior to the fossa ovalis area and is called a superior sinus venosus ASD if there is an absence of the superior border or an inferior sinus venosus ASD if the inferior border is deficient.1 The key to diagnosis is the presence of overriding of the IVC across the intact atrial septum and the defect outside the confines of the fossa ovalis area.2 However, accurate diagnosis by echocardiography remains a challenge. Two-dimensional echocardiography might reveal an ASD with an unusual location, raising the suspicion of sinus venosus 457.e4
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Figure 1 (A) Transthoracic 2D echocardiography from the apical 4-chamber view showed a defect in the posteroinferior portion of the atrial septum (white arrow). The coronary sinus (CS) was dilated (asterisk). (B) Color Doppler echocardiography revealed a large shunt from the left atrium to the right atrium (RA). (C) Transthoracic 3D echocardiographic image viewed from the lateral aspect of the RA toward the atrial septum demonstrated an ASD (arrowheads), posterior to the dilated CS (asterisk) and directly communicating with the orifice of the IVC. (D) Multidetector computed tomography showed a dilated CS. (E) The ASD (black arrow) in the posteroinferior portion of the atrial septum was just above the orifice of the IVC. The drainage of the right lower pulmonary vein is normal. LV, Left ventricle; RV, right ventricle. ASD, but its relationship with nearby structures is usually difficult to delineate. Transesophageal echocardiography would theoretically provide better visualization of the sinus venosus ASD.3,4 However, the invasiveness and long procedure time are major drawbacks of transesophageal echocardiography. We demonstrated that transthoracic 3D echocardiography could provide accurate diagnosis of inferior sinus venosus ASDs by detailed appreciation of their relations with the IVC, the pulmonary veins, and the muscular border of the fossa ovalis. Recognition of the nature of interatrial communication and pulmonary vein connection is crucial before planning surgical procedure. These 2 cases not only remind physicians of the importance of indentifying a potentially treatable cause of pulmonary hypertension but also highlight the potential value of transthoracic 3-dimensional echocardiography in providing better appreciation of the anatomy and nearby structures around
an inferior sinus venosus ASD compared with the conventional echocardiography. REFERENCES 1. Van Praagh S, Carrera ME, Sanders SP, Mayer JE, Van Praagh R. Sinus venosus defects: unroofing of the right pulmonary veins—anatomic and echocardiographic findings and surgical treatment. Am Heart J 1994;128:365-79. 2. al Zaghal AM. Li J, Anderson RH, Lincoln C, Shore D, Rigby ML. Anatomical criteria for the diagnosis of sinus venosus defects. Heart 1997;78:298-304. 3. Nanda NC, Ansingkar K, Espinal M, Jindal A, Puri VV, Aaluri S, et al. Transesophageal three-dimensional echo assessment of sinus venosus atrial septal defect. Echocardiography 1999;16:835-7. 4. Kessel-Schaefer A, Linka A, Pretre R, Buser P. Inferior sinus venosus defect associated with incomplete cor triatriatum dexter and patent foramen ovale. Eur J Echocardiogr 2006;7:239-42.
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Figure 2 (A) Transthoracic color Doppler echocardiography from the apical 4-chamber view showed a defect in the posteroinferior portion of the atrial septum with a large shunt from the left atrium to the right atrium (RA). (B) Transthoracic 3D echocardiographic image viewed from lateral aspect of the RA toward the atrial septum showed an ASD (black arrowheads), posterior to the dilated coronary sinus (CS) (asterisk) and directly communicating with the IVC. The orifice of the right lower pulmonary vein (RLPV) (white arrowheads) was just above the orifice of the IVC. (C) Three-dimensional echocardiographic image viewed from the orifice of the IVC toward the roofs of the atria demonstrated that both the IVC and the RLPV (white arrowheads) overrode the atrial septum. (D) Multidetector computed tomography showed that the ASD (arrow) was located at the posterior portion of the atrial septum. (E,F) The RLPV overrode the atrial septum and directly communicated with the ASD (arrow). LV, Left ventricle; RV, right ventricle.
