**1. Introduction**

Congenital heart defects (CHDs) are defined as anatomic malformations of either the heart or great vessels, which occur while intrauterine development of the heart is taking place [1]. This is regardless of the age at which the CHD manifests. Typical examples of CHDs are ventricular septal defect and coarctation of the aorta. Many studies were performed to determine the incidence of CHDs; these investigations indicate an incidence of 0.8% of live births [2]. This would result in the birth of approximately 40,000 babies in the United States alone, and over 1,000,000 babies are born with a heart defect worldwide. There is no evidence for any differences in the prevalence of CHD among continents or between racial groups [3]. Recent description of pulse oximetry screening of newborn babies prior to discharge from the hospital has resulted in early identification of critical CHDs [4–6]. This adds to the early detection strategies offered by fetal echocardiography [7]. Approximately half of the patients with CHDs may be addressed by providing ordinary medications and clinical follow-up without major therapeutic interventions. Nevertheless, the outstanding half formerly needed surgery, and some requiring open-heart procedures through cardiopulmonary bypass. Subsequently, following the development of percutaneous methods [8–12], half of these children (i.e., 25% of the total) are being addressed by percutaneous, transcatheter techniques that are less invasive than surgery.

Availability of highly sensitive noninvasive diagnostic tools such as echo-Doppler studies [13–16], magnetic resonance imaging (MRI) [17, 18], computed tomography (CT) [19, 20]; identification of CHD in the fetus by echo [7]; early detection of neonates with serious heart disease [21, 22], including pulse oximetry screening of the neonates prior to discharge from the hospital [4–6] and their rapid transport to tertiary care centers [21, 22]; advances in transcatheter interventional procedures [8–12]; improvements in pediatric cardiac anesthesia [23, 24]; and extension of complicated surgical procedures to treat children with complex CHDs [25] have resulted in the successful management of all children with heart disease. Consequently, almost all CHDs are diagnosed and "corrected." Defects that cannot be completely corrected can be effectively palliated [26] or cardiac transplantation performed [27–29]. The last five decades have seen a great many advances and as mentioned above, these resulted in the increased survival of children with CHD. The purpose of this book on

"Congenital Heart Defects: Recent Advances" is to present some of these advances in an easily readable format for the physicians and other health-care personnel interested in the care of infants, children, and adults with congenital heart disease.

While a number of chapters were contributed to this book, not all the advances that occurred during the last 50 years could be included; this is largely related to the method by which the authors were recruited and chapter titles were selected and limitations of the space. Yet, the authors of the book chapters and I hope that the discussed matter is helpful to the reader and help him/her in the care of the patients that they are involved in.
