Heterotaxy: fluctuat nec mergitur.

The International Pediatric and Congenital Cardiac Code (IPCCC) states that visceral heterotaxy is defined as "a congenital malformation in which the internal thoraco-abdominal organs demonstrate abnormal arrangement across the left-right axis of the body. By convention, in congenital cardiology, heterotaxy syndrome does not include patients with complete mirror-imaged arrangement of the internal organs along the left-right axis also known as "total mirror imagery" or "situs inversus totalis"." [www.ipccc.net]In patients with heterotaxy, it is important to describe both the cardiac relations and the junctional connections of the cardiac segments, with documentation of the arrangement of the atrial appendages, the ventricular topology, the nature of the unions of the segments across the atrioventricular and the ventriculoarterial junctions, the infundibular morphologies, and the relationships of the arterial trunks in space. Particular attention is required for the venoatrial connections, since these are so often abnormal. The relationship and arrangement of the remaining thoraco-abdominal organs, including the lungs, the spleen, the liver, and the intestines, also must be described separately, because, although common patterns of association have been identified, there are frequent exceptions to these common patterns. Therefore, in patients with heterotaxy, it is important to describe each thoracic and abdominal organ independently.