The Department of Emergency Medicine at Carolinas Medical Center is passionate about education! Dr. Michael Gibbs is a world-renowned clinician and educator and has helped guide numerous young clinicians on the long path of Mastery of Emergency Medical Care. With his oversight, the EMGuideWire team aim to help augment our understanding of emergent imaging. You can follow along with the EMGuideWire.com team as they post these educational, self-guided radiology slides or you can also use this section to learn more in-depth about specific conditions and diseases. This Radiology Reading Room pertains to Situs Anomalies and is brought to you by Dominic Nicacio, MD, Andrew Yde, MD, Jorge Alegria, MD, and Laszlo Littmann, MD.

1. Situs Anomalies
Michael A. Gibbs, MD, Lead Editor
Carolinas Medical Center Imaging Mastery Project
Dominic Nicacio, MD, Andrew Yde, MD,
Jorge Alegria, MD Laszlo Littmann, MD
Departments of Emergency Medicine & Internal Medicine
Sanger Heart & Vascular Institute
Carolinas Medical Center

2. Visit Our Website
www.EMGuidewire.com
For A Complete Archive Of Chest X-Ray Presentations And Much More!

3. Airway
Bones
Cardiac
Diaphragm
Effusion
Foreign body
Gastric
Hilum

4. It’s All About The Anatomy!

5. Embedded References
Maldijan PD. Approach To Dextrocardia In Adults. American Journal Of Radiology. 2007; 188;S39-
S49.
Winter JE. Recognition of Anterior STEMI in Dextrocardia and the Importance of Right-Sided Chest
Leads. Journal of The American College of Cardiology. 2020; 2(8):1222-1226.
Gentile BA. Situs Inversus Totalis. New England Journal of Medicine. 2019; 380:e45.
Celik AI. Acute Anterior Myocardial Infarction in a Patient with Dextrocardia and Situs Inversus.
Journal of the American College of Cardiology. 2020; 2(8):1220-1221.

6. Situs Nomenclature
Determined by the relationship between the atria and adjacent organs:
• Situs solitus
• Situs solitus with dextrocadia
• Situs inversus with dextrocardia
• Situs inversus with levocardia
• Situs ambiguous

7. Situs Solitus
• Normal anatomy
Situs Solitus With Dextrocardia
• Mirror image positioning of the heart only
Situs Inversus With Dextrocardia [Totalis]
• Mirror image positioning of all thoracoabdominal viscera
Situs Inversus With Levocardia
• Mirror image positioning of all abdominal viscera
• Descending aorta on the right (concordant with situs inversus)
Situs Ambiguous
• Also called situs heterotaxy, any arrangement of organs between the spectrum
of situs solitus (normal positioning) and situs inversus totalis

8. dextrocardia, the descending aorta, cardiac apex, and stomach are all on the right. In situs solitus with dextrocardia, the descending aorta and stomach are on the left (normal), but the
cardiac apex is on the right. In situs inversus with levocardia, the descending aorta and stomach are on the right (situs inversus), but the cardiac apex is on the left.
Figure 3-8 Schematic illustrations of the anatomic relationships of the descending aorta, left atrium, cardiac apex, and stomach in the four basic cardiac positions (normal and three
malpositions). In situs solitus, the descending aorta, left atrium, cardiac apex, and stomach are all on the left. In situs inversus with dextrocardia, the descending aorta, left atrium, cardiac
apex, and stomach are all on the right. In situs solitus with dextrocardia, the descending aorta, left atrium, and stomach are on the left (normal), but the cardiac apex is on the right. In situs
inversus with levocardia, the descending aorta, left atrium, and stomach are on the right (situs inversus), but the cardiac apex is on the left. (RA = right atrium; LA = left atrium; RV = right

10. Situs Solitus With
Dextrocardia

14. 3-11 X-ray from a 2-year-old girl in situs inversus with levocardia. The stomach (S) is on the right and the liver (L) is on the left, but the heart (apex) is to the left of mid
midiaphragm is lower than the right hemidiaphragm because the cardiac apex is on the left. The descending thoracic aorta (DAo) is on the right (concordant for situs inversus
of the ascending aorta (AAo) indicates a discordant d-bulboventricular loop.
Situs Inversus And Levocardia: The stomach (S) is on the right and the liver (L) on the left. The left
hemidiaphragm is lower because the cardiac apex is no the left. The descending thoracic aorta (DAo) is on
the right (concordant with situs inversus, but the ascending aortic (AAo) is on the left.

15. Primary Ciliary Dyskinesia
• Primary ciliary dyskinesia is an inherited disorder of abnormally
functioning cilia
• Abnormally functioning cilia of the epithelial cells necessary for
correct thoracoabdominal orientation during embryogenesis
• Approximately 25% of patients with situs inversus totalis have
primary ciliary dyskinesia
• Kartagener’s Syndrome defines a subset of primary ciliary dyskinesia
patients with with classic triad: situs inversus totalis, sinusitis and
bronchiectasis

16. Kartagener’s Syndrome

17. Epidemiology
Dextrocardia Situs Inversus Totalis
Incidence 1 in 12,000 1 in 10,000
Genetic Inheritance Inconclusive Autosomal recessive in patients
with Primary Ciliary Dyskinesia
Risk Factors  Males and females are affected equally
 Maternal cocaine use is associated with an increased
incidence
Associated Conditions  Transposition of great vessels, double inlet ventricles,
tricuspid atresia, polysplenia

19. Clinical Presentation
Dextrocardia1,2,3:
 Asymptomatic
 Characteristic ECG findings
Situs Inversus1,2,3:
 Opposite sided abdominal complaints in acute hepatobiliary,
gastric, and appendiceal pathology
Kartagener’s syndrome1,2:
 Chronic sinusitis and otitis media
 Bronchiectasis
 Infertility common in males
1Right-sided heart tones.
2Sequelea of any other associated congenital heart disease.
3Characteristic ECG findings.

20. Situs Anomalies
Cases Studies From Carolinas Medical Center

22. Normal Position Situs Solitus
Liver
Diaphragm Higher
On The Right
Gastric Bubble
Cardiac Apex
Descending Aorta
On The Left
Spleen

23. 61-Year-Old
At Cardiology
Appointment.

24. Diaphragm Higher
On The Left
Situs Inversus With Dextrocardia
Liver
Gastric Bubble

25. LiverSpleen
Abdominal Transposition
Dextrocardia
Situs Inversus Totalis

26. Healthy 33-
Year-Old
With Chest
Pain.

27. Situs Inversus With Dextrocardia
Gastric Bubbler
Diaphragm Higher
On The Left
Liver

28. Healthy 42-
Year-Old Has
An Incidental
Finding On
Chest X-Ray

29. Situs Inversus With Dextrocardia
Gastric Bubbler
Liver

30. 65-Year-Old
At His
Cardiology
Follow-Up
Visit.

31. Diaphragm Higher
On The Left
Situs Inversus With Dextrocardia
Gastric Bubbler
Liver

32. Healthy 45-
Year-Old
Undergoes
Preoperative
Screening.

33. Situs Solitus With Dextrocardia
Gastric Bubble
Liver

34. 33-Year-Old
With
Congenitally
Corrected
Transposition
Of The Great
Vessels.

35. Situs Solitus With Dextrocardia
Gastric Bubble
Liver

36. Liver
Situs Solitus And Dextrocardia

37. Classic ECG Findings
• Inverted complexes in I, aVL
• Upright complexes in aVR
• Low voltage V3-V6
• No R wave progression
• Right axis deviation
• Normal EKG with lead reversal

46. If You Have Interesting Cases Of Situs Anomalies We Invite You To Send A Set
Of Digital PDF Images And A Brief Clinical History To:
michael.gibbs@atriumhealth.org
Your De-Identified Case(s) Will Be Posted On Our Education Website And You
And Your Institution Will Be Recognized!