Cor Triatriatum Dexter, Cor Triatrium Dexter

Cor triatriatum is an uncommon malformation caused by the division of the right (dexter) or left (sinister) heart atrium into two chambers by an abnormal membrane. In cor triatriatum dexter (right-side triatrial heart), the right atrium is partitioned into two compartments, effectively creating a triatrial heart. It is well documented in dogs. Affected breeds include Chow Chow, Cocker Spaniel, English Bulldog, German Shepherd Dog, German Shorthaired Pointer, Golden Retriever, Greyhound, Rottweiler and mixed breed.

The most common clinical sign is ascites (an abnormal accumulation of fluid in the abdominal cavity). Another common sign is enlargement of the liver.³ Exercise intolerance, lethargy, fainting, distended abdominal veins, coughing, breathing problems, growth retardation and sometimes diarrhea have been reported in affected animals. Some dogs may have few or no symptoms. Successful therapy requires removal of the abnormal membrane to eliminate blood flow obstruction. ²

Although several methods have been used to treat cor triatriatum dexter in dogs, the surgical correction is considered a reliable approach. Cor triatriatum dexter can be successfully treated by balloon dilatation (stretching a constricted artery) provided that it is recognized early enough.⁴ Clinical signs improve within days and are sustained in the long term.

References

1. Magnus Michaelsson, Siew Yen Ho. Congenital Heart Malformations in Mammals: An Illustrated Text
2. Richard W. Nelson, C. Guillermo Couto. Small Animal INternal Medicine
3. Cor triatriatum dexter in an English Bulldog puppy: case report and literature review. Robert B. Duncan, Jr., Larry E. Freeman, Jeryl Jones, Martha Moon
4. Skrzypczak, P., Pasawska, U., Atamaniuk, W., Nicpon, J. Diagnosis and treatment of cor triatriatum dexter in dogs