IS case 480: Situs inversus totalis

Durga Singh, MD

University of Rochester


Imaging Sciences URMC 2010
Publication Date: 2010-08-30

History

Patient is a 46-year-old patient with atrial mass seen for preoperative evaluation.

Findings

See images

Diagnosis

Situs inversus totalis

Discussion

Situs inversus totalis is a condition where the normal arrangement of the cardiac atria, lungs, and certain visceral organs is reversed in a "mirror image". This causes a left-sided systemic atrium, trilobed lung, liver, gallbladder, and inferior vena cava. It was first observed by Aristotle, and is associated in about 20% of cases with primary ciliary dyskinesia (Kartagener syndrome). Bronchiectasis as a result of frequent pulmonary infections is often a finding with primary ciliary dyskinesia. There is no gender or racial predilection, and it occurs in 0.01% of the population, with incidence of congenital heart disease of 3-5%. Situs inversus can occur with levocardia or with dextrocardia. In determining dextro/levocardia, the direction of the base-to-apex axis is considered. Another categorization of situs is situs ambiguous or heterotaxy, where the atrial shape is unclear, malrotated bowel is present, with a multiple or absent spleen, and a midline liver. Situs ambiguous is further divided into asplenia (right isomerism) or polysplenia (left isomerism).

References

  1. Applegate KE, Goske MJ, Pierce G, Murphy D. Situs revisited: imaging of the heterotaxy syndrome. Radiographics. 1999 Jul-Aug;19(4):837-52; discussion 853-4. PMID: 10464794
  2. Sanders WJ, Poorman DH. Complete situs inversus with anomalous right common carotid artery. Arch Surg. 1968 Jan;96(1):86-90. PMID: 5638241

2 images