A coumadin ridge, also called warfarin ridge or left lateral ridge, is a band-like embryological remnant in the left atrium between the left superior pulmonary vein and the left atrial appendage. It is considered an anatomical variant.
The ridge is formed by the coalition of the left superior pulmonary vein and left atrial appendage, which results in a lateral fold of left atrial wall tissue. The ridge contains the ligament of Marshall, autonomic nerve bundle, and small atrial or sinoatrial node artery.
Echocardiography and MRI
The usual appearance of a coumadin ridge is a band-like structure with a thin proximal part and a bulbous distal part that resembles a cotton-tip applicator. This is known as the "Q-tip sign" on transoesophageal echocardiogram.
Cardiac MRI using a "bright blood" gradient echo pulse sequence, is useful in demonstrating the ridge. Contrast injection is usually unnecessary but may be helpful in identifying an organized thrombus or tumour in the left atrial appendage.
A prominent coumadin ridge may protrude into the endocardial surface of the left atrium and can be mistaken for a thrombus or mass on imaging 1-4. The unique location of the coumadin ridge between the left superior pulmonary vein and left atrial appendage is an important clue to its identification.
History and etymology
It was called "coumadin" or "warfarin" ridge since it was commonly misdiagnosed as a thrombus, which resulted in unnecessary anticoagulation.
Possible considerations include:
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- 2. Lodhi AM, Nguyen T, Bianco C, Movahed A. Coumadin ridge: An incidental finding of a left atrial pseudotumor on transthoracic echocardiography. World journal of clinical cases. 3 (9): 831-4. doi:10.12998/wjcc.v3.i9.831 - Pubmed
- 3. Gupta S, Plein S, Greenwood JP. The Coumadin Ridge: An Important Example of a Left Atrial Pseudotumour demonstrated by Cardiovascular Magnetic Resonance Imaging. Journal of radiology case reports. 3 (9): 1-5. doi:10.3941/jrcr.v3i9.210 - Pubmed
- 4. McKay T, Thomas L. 'Coumadin ridge' in the left atrium demonstrated on three dimensional transthoracic echocardiography. European journal of echocardiography : the journal of the Working Group on Echocardiography of the European Society of Cardiology. 9 (2): 298-300. doi:10.1016/j.euje.2006.10.002 - Pubmed