SearchDiagnosing Thrombosis in Atrial Fibrillation
Diagnosing a thrombus in the atria
In atrial fibrillation (AF), thrombi tend to form in the left atrium far more often than in the right atrium; clots forming in the left atrium pose a risk of cerebral or systemic emboli.22, 49 Transoesophageal echocardiography (TOE) is a more sensitive test than transthoracic electrocardiography for detecting thrombi within the atria. For this reason, TOE is generally recommended to visualise the heart before any treatment intended to restore normal sinus rhythm (eg, electric cardioversion). TOE involves placing an ultrasound transducer into the oesophagus directly behind the heart.
Other findings from TOE often associated with thromboembolism are reduced left atrial flow velocity and spontaneous echo contrast, which is thought to be caused by fibrinogen-mediated red blood cell aggregation.50
Thrombus in left atrium
- 22 - Fuster V, Rydén LE, Cannom DS, et al. ACC/AHA/ESC 2006 Guidelines for the Management of Patients with Atrial Fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Revise the 2001 Guidelines for the Management of Patients With Atrial Fibrillation): developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society. Circulation. 2006;114(7):e257-e354.
- 49 - Agmon Y, Khandheria BK, Gentile F, Seward JB. Echocardiographic assessment of the left atrial appendage. J Am Coll Cardiol. 1999;34(7):1867-1877.
- 50 - Rastegar R, Harnick DJ, Weidemann P, et al. Spontaneous echo contrast videodensity is flow-related and is dependent on the relative concentrations of fibrinogen and red blood cells. J Am Coll Cardiol. 2003;41(4):603-610.
