A novel approach to the diagnosis of left atrial appendage thrombus using contrast echocardiography and power Doppler imaging

BACKGROUND: Transesophageal echocardiography is performed routinely among patients with atrial fibrillation (AF) in order to exclude left atrial appendage (LAA) thrombus prior to cardioversion. Because assessment for LAA thrombus is dependent upon the experience of the operator and is therefore subjective, there remains a subset of patients in whom the diagnosis may not be definitive. The purpose of this report is to present a novel technique which may aid in the confirmation and/or exclusion of LAA thrombus using contrast echocardiography (CE) and power Doppler (PD) imaging. METHODS: TEE imaging of the LAA appendage was performed in 3 patients. By visual inspection, the presence of the thrombus was absent (patient one), equivocal (patient two) and definite (patient three). Contrast echocardiography with Definity and power Doppler imaging was performed to aid in the confirmation and/or exclusion of thrombus in these 3 patients. RESULTS: CE alone was useful in confirming the absence and presence of LA thrombus determined by visual inspection in patients one and three, respectively. CE in conjunction with PD imaging was useful in identifying the presence of LAA thrombus (by showing a filling defect and the absence of flow in the tip) in the patient with equivocal results by visual inspection CONCLUSION: Contrast echocardiography alone may be useful in confirming and/or excluding the presence of LAA thrombus among patients with AF. CE with PD imaging provides incremental information in aiding in the diagnosis when the conventional images are equivocal.