ABSTRACT
A systematic approach to morphological description of congenital heart diseases (CHD) particularly complex CHD. The heart is considered in three segments: the atrial segment, the ventricular segment and the arterial segment. The philosophy of segmental analysis is founded on morphology. The chambers are recognized according to their morphology (leftness or rightness) rather than their position. Normal position of the viscera with the liver on the right. The cardiac situs is determined by the position of the morphological right atrium. In the presence of situs solitus, the morphological right atrium is on the right of the morphological left atrium, and the morphological right lung is on the right and the morphological left lung on the left. The situs is indeterminate in the setting of isomerism (bilateral visceroatrial symmetry), there is either left isomerism or right isomerism. Isomerism describes a paired, mirror-image set of normally single or nonidentical organ systems (atria, lungs, viscera) and is frequently associated with other abnormalities.
