A 34-year-old woman was seen in the outpatient clinic for a 1-year history of worsening dyspnea on exertion (New York Heart Association class III), 2-pillow orthopnea, bilateral pedal edema, and occasional episodes of palpitations. Her transthoracic echocardiogram revealed an ostium secundum atrial septal defect (ASD), significant enlargement of the right ventricle, evidence of left-to-right shunt with a pulmonary to systemic flow (Qp/Qs) ratio of 2.3, and normal left ventricular ejection fraction (Figure 26-1). Transesophageal echocardiogram confirmed an ostium secundum ASD of 18-mm diameter with sufficient tissue rims and ruled out additional congenital defects (Figure 26-2). She underwent successful percutaneous closure of her ostium secundum ASD with a 22-mm atrial septal occluder device using intracardiac echocardiography guidance. After 6 months, she remains asymptomatic and a repeat transthoracic echocardiogram revealed no residual shunt across the interatrial septum and significant reduction in right ventricular volume.
Transthoracic echocardiogram of a patient with an ostium secundum atrial septal defect (ASD). (A) Apical 4-chamber view with color Doppler demonstrates blood flow across the central portion of the interatrial septum consistent with an ostium secundum ASD. Two-dimensional images from the apical 4-chamber view (B) and the short axis view (C) revealed severe right ventricular enlargement. ASD, atrial septal defect; LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle.
Transesophageal echocardiogram of a patient with an ostium secundum atrial septal defect (ASD). Two-dimensional (A) and color Doppler (B) images from the bicaval view showed an ostium secundum ASD of 18 mm in diameter with adequate superior and inferior rims and left-to-right shunt. (C) Short axis view at the level of the ascending aorta demonstrated sufficient anterior (aortic) and posterior rims. (D) Ostium secundum defect viewed with a 3-dimensional image. AO, aorta; ASD, atrial septal defect; LA, left atrium; RA, right atrium.
EPIDEMIOLOGY, CLINICAL PRESENTATION, AND DIAGNOSIS
Atrial septal defects (ASDs), a congenital deficiency of the interatrial septum, allow intracardiac shunting and account for nearly one third of congenital heart defects in adults.1,2 Excluding bicuspid aortic valve and mitral valve prolapse, ASDs are the most frequently diagnosed congenital abnormalities in the adult population and encompass 4 distinct types of defects of the interatrial septum (Figure 26-3). Ostium secundum ASDs are the most common type, accounting for approximately 75% of all ASDs, and are generally the result of an underdeveloped septum secundum and/or excessive reabsorption ...