[Detection of thrombosis of the left atrium in mitral valve stenosis. Particular value of transesophageal echography].

This retrospective study assessed the prevalence of left atrial thrombi in mitral stenosis and evaluated the diagnostic value ot the main means of investigation Five hundred and eighty-one patients underwent open heart surgery over a 10 year period. The prevalence of atrial thrombi was 7%, the majority (60%) being located in the left atrial appendage. The sensitivity of transthoracic echocardiography for detecting thrombi in the left atrial cavity was satisfactory (65%) but was very poor for detecting thrombi in the left atrial appendage (4%). The results of invasive investigations (atrial angiography and coronary angiography) are no better. Without any doubt, transoesophageal echocardiography, performed in 101 patients in this series, has transformed these results (sensitivity 83%, specificity 97%). False negatives in this study mainly concerned small thrombi adherent to the atrial wall. Under these conditions, it would seem reasonable to propose transoesophageal echocardiography to all patients with mitral stenosis complicated by an embolic event or for those for whom percutaneous commissurotomy is suggested.