Prevalence of Secundum Atrial Septal Defect and Associated Findings

The goal of this chapter is to review data regarding the current prevalence estimates for secundum type atrial septal defect (ASD) and to give the reader a sense as to how these prevalence data compare relative to other common cardiac defects. This chapter will also review the current understanding of cardiac and non-cardiac findings known to be associated with secundum ASD. It is recognized that the prevalence estimates of cardiac defects have been impacted by the routine utilization of color flow Doppler-echocardiography in current clinical practice. This is particularly true for certain cardiac anomalies such as secundum ASD that frequently occur in asymptomatic infants and children. Several studies have indeed documented a significant increase in the apparent prevalence of congenital heart defects in general and specifically for certain common phenotypes including secundum ASD (Hoffman & Kaplan, 2002; Wren et al., 2000; Correa et al., 2007). Further, these studies have concluded that much of these increases are likely secondary to better ascertainment in recent years. This chapter will review the most recent estimates of the prevalence of secundum ASD using information obtained from a population-based surveillance system using strict definitions of what constitutes a secundum ASD. This chapter will also review a detailed list of what is presently known about the associated findings and potential risk factors for the development of secundum ASD.