Crista terminalis

The crista terminalis is a smooth muscular ridge in the superior aspect of the right atrium, formed following resorption of the right valve of the sinus venosus. It represents the junction between the sinus venarum, the "smooth" portion of the right atrium derived from the embryologic sinus venosus, and the heavily trabeculated right atrial appendage.

Coursing between the caval orifices, it divides the pectinate muscle origin and the right atrial appendages in the right atrium. Its identification is significant in the determination of atrial situs.

Radiographic features

Cirsta terminalis is depicted as a linear structure in the posterolateral right atrial wall. It divides the right atrium into smooth posteromedial and trabeculated anterolateral portions.

Related pathology

While its presence is of no pathologic significance, unusual prominence of the crista terminalis has been associated with:

  • atrial fibrillation and/or flutter
    • implicated as the ectopic focus of arrythmogenesis
  • inappropriate sinus tachycardia (IST) 2
Anatomy: Thoracic

Anatomy: Thoracic

Article information

rID: 31463
System: Cardiac
Section: Anatomy
Synonyms or Alternate Spellings:
  • Terminal crest

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