In this book, the authors have gathered and present topical research in the study of the molecular determinants, impact of environmental factors and non-surgical interventions relating to atrial and ventricular septal defects. Topics discussed in this compilation include the molecular mechanisms of ventricular septal defects; maternal characteristics and use of drugs and septum heart defects in children; non-surgical closure of atrial septal defects in children; and the aetiology and percutaneous closure of atrial and ventricular septal defects.