Atrial Ridges

Crista Terminalis

The crista terminalis is a smooth muscular ridge within the right atrium that represents the line of fusion between the trabeculated primitive right atrium and the smooth-walled right atrium arising from the sinus venosus. It is oriented in the cradiocaudad direction and extends from the superior vena cava to the inferior vena cava.

It can often be seen extending into the right atrium. When prominent, it may be mistaken for a tumor or thrombus.

Warfarin (Coumadin) Ridge

The warfarin (Coumadin) ridge is a ridge of smooth muscle found along the wall of the left atrium at the junction of the left atrial appendage and the entrance of the left superior pulmonary vein. It derives its name from its misidentification as a thrombus and subsequent anticoagulation therapy with warfarin.

It may also be mistaken for a pedunculated mass arising from the lateral wall of the left atrium.

References

Broderick LS, Brooks GN, Kuhlman JE. Anatomic pitfalls of the heart and pericardium. Radiographics. 2005 Mar-Apr;25(2):441-53.