Comparative value of transthoracic and transesophageal echocardiography for the detection of left atrial thrombi and the assessment of left atrial appendage function in patients with mitral stenosis and mitral valve replacement

The aim of this prospective study was to compare the value of transthoracic and transesophageal echocardiography for detecting left atrial appendage thrombi in patients with mitral stenosis or mitral valve replacement. Transthoracic and transesophageal echocardiography were performed in 23 consecutive patients suspected of having arterial embolization or dysfunction of the mitral valve prothesis. The feasibility of imaging the left atrial appendage, recording its peak flow velocities, and identifying left atrial appendage thrombi was determined for both methods. Imaging of the complete left atrial appendage was feasible in 87% of patients by transthoracic echocardiography and in 91% by transesophageal echocardiography. Transthoracic and transesophageal echocardiography were concordant in the detection of eight left atrial appendage thrombi. Transesophageal echocardiography detected one additional thrombus that had been missed by the transthoracic examination. In patients with optimal transthoracic echogenicity, the specificity and sensivity of detecting left atrial appendage thrombi were 100% and 88%, respectively. Transthoracic recording of left atrial appendage peak flow velocities was feasible in 52%. New-generation echocardiographic systems allow transthoracic detection of left atrial appendage thrombi and the assessment of left atrial appendage function in most patients with mitral stenosis and mitral valve replacement.