Understanding normal and abnormal cardiac structures is best achieved through pathological specimens. Some cardiologists or cardiac surgeons are fortunate enough to work at centers where hearts from autopsies are preserved and catalogued for teaching purposes, but most practitioners still need to form a mental picture of the cardiac pathology and morphology. Actually, specific anatomic and diagnostic issues often remain in question after cautious preoperative and serial studies, and some physicians frequently fail to perform this mental exercise consistently. If we have a model which presents the cardiac anatomy and segmental relationship in a perspective view with a simple hand-drawn threedimensional model to improve the understanding of the complex heart, it will be accessible to inexperienced staff and medical students and also to patients' families, and it will also save the considerable cost of image reconstruction. Some cardiac defects such as ASD, VSD, PDA, or TAPVR are easily visualized after echocardiographic examinations, but others remain challenges, especially hearts with misaligned cardiac segments and hearts with a double outlet right ventricle. In order to classify and clearly understand the variants of congenital cardiac defects, Dr. Van Praagh introduced three cardiac segments to establish a cardiac set. He used the coding system of the atrium, ventricle and great vessel to describe the hemodynamics and relationships of cardiac anatomy. The first code represents the atrium status including situs solitus or inversus. The second code represents the ventricular status including ventricular D-loop and L-loop. The third code represents the relationships of the great arteries including the aorta located anteriorly to the pulmonary trunk (Dmalposition or L-malposition), and the aorta located posteriorly to the pulmonary trunk (solitus or inversus position). The system clearly categorizes complex cardiac defects, but different cardiac anomalies can be present under the same coding conditions and the hemodynamics of the codes and the connections between ventricular-arterial segments are still not easily understood by inexperienced personnel because the system lacks stereotactic structures. This is why we wished to develop a simple three-dimensional model to depict complex hearts. Before creating the models of variant congenital cardiac defects, we needed to determine the stereography of anomaly heart. We found the transverse cross-section of www.intechopen.com Echocardiography-New Techniques 186 heart at the atrio-ventricular junction offers the best reconstructive level for stereo-images because of its coverage of most cardiac structures and defects. From the picture, we can clearly visualize the heart with its specific relationships at the atrio-ventricular and ventricular-arterial segments. For the atrium, we used a broad-base triangular appendage to indicate the morphological right atrium; a finger and tube-like structure indicates the morphological left atrium. For the atrio-ventricular valves, we us...
