Atrial Situs

Question 1

Atrial situs refers to the

Answer 1

location /position of the atria in relation to nearby anatomy

Question 2

“Atrial situs solitus” the arrangement is

Answer 2

Normal atrial arrangement

Question 3

“Atrial situs inverses” the arrangement is

Answer 3

Atria are transposed

Question 4

“Situs ambiguus” describes

Answer 4

everything in-between

Question 5

How are the left and right atria best distinguished apart from one another?

Answer 5

by their appendage.

-Right atria appendage is broad base triangle shape
-left atria appendage is narrow and finger like

Question 6

Left atria with left isomerism

Answer 6

Bilateral left sidedness
bilateral left atrial appendages
-Absent Sinus node
-ipsilateral pulmonary veins
-interruption of the IVC with azygos continuation
-atrioventricular septal defect
-pulmonary outflow obstruction
-bilateral bi lobed lungs
-polyspleens
-congenital complete heart block

Question 7

Azygos Vein

Answer 7

present during interrupted IVC.
-runs parallel to the AO
-takes flow back to the SVC

Question 8

Right atria with right isomerism

Answer 8

Bilateral right sidedness
-bilateral RA appendage
-bilateral SVC (LSVC> LA)
-bilateral IVC (hepatic veins drain into LA )
-Absent (unroofed) coronary sinus
-TAPVR
-Bilateral trilobed lungs
-usually absent spleen
-Unbalanced AVSD- right dominate (think DORV)
-pulmonary outflow obstruction/ atresia
-ventricle - arterial connection abnormalities (DTGA)

Question 9

Vertical Vein

Answer 9

connection between pulmonary veins to the innominate vein to SVC