This chapter focuses on noncyanotic congenital heart disease with a basic description of the epidemiology, embryology, clinical manifestation, diagnostic testing, management, treatment, and prognosis of each lesion. The intent is to provide a framework for the major types of noncyanotic congenital heart disease, ranging from septal defects, left ventricular outflow tract (LVOT) obstruction disease, and right ventricular outflow tract obstruction disease. The chapter forms a guide for managing neonates with these common heart conditions.
The atrial septal defect (ASD) is one of the first forms of congenital heart disease that was corrected surgically. It represents a communication between the left and right atria and does not usually manifest in the neonatal period unless there is associated congenital heart disease, which usually makes it difficult to diagnose. There are 3 major types: secundum ASD, primum ASD, and sinus venosus ASD. The primum ASD is discussed as a part of the atrioventricular canal (AVC) defect (Figure 19-1).
This 3-dimensional echocardiogram image depicts the interatrial septum from the perspective of the right atrial side. The superior vena cava (SVC) drains superiorly into the right atrium, while the inferior vena cava (IVC) drains from below. The fossa ovalis is central, and a secundum atrial septal defect (ASD) would lie in region 1. A superior or inferior sinus venosus ASD is located in regions 2 or 3, respectively. The primum ASD is located anteroinferiorly at region 5. The rare coronary sinus (CS) ASD, not discussed in this chapter, is located near the CS. The aorta (Ao), which is anteriorly located, is diagrammed as a point of reference. EV, Eustachian valve. (Reproduced with permission from Faletra et al.160)
The ASD represents the second-most-common form of congenital heart disease behind the ventricular septal defect (VSD). The occurrence is between 3% and 4.1% of 1000 live births1,2 and 7% and 15% of all congenital heart disease cases.3,4 For defects that are larger and measure over 5 mm in diameter, there tends to be a female predominance.5,6 The secundum ASD is by far the most common type (Table 19-1). Nearly 1 of every neonates will have an atrial communication that is difficult to distinguish from a patent foramen ovale.7 Approximately 15% of trisomy 21 patients will have a secundum ASD, and 1% of ASD patients will have Holt-Oram syndrome.8 Of note, patients with Holt-Oram tend to have very large ASDs and can have a common atrium with no wall separating the atria.
Table 19-1Common Forms of Atrial Septal Defect (ASD) (%)