This Module is Module 3 in a 13 module eCourse series on Stats, Cardiac Cycle, Basic Echo Exam. For information on the full Pediatric Echocardiography, please click here. This module will discuss cardiac development with special emphasis on those areas of cardiac embryology that lead to certain types of congenital defects. Understanding this area can greatly enhance the understanding of certain defects. The fetal circulation is another important part of early development. It is important to understand the normal physiology of the fetus in order to understand how certain heart defects survive until birth and how they can be maintained after birth.