Role of echocardiography in systemic arterial embolism - A review with recommendations

The ability of echocardiography to diagnose sources of embolism and the rol e of the examination in the prediction of thromboembolism are reviewed. In addition, the yield of transthoracic (TTE) and transoesophageal echocardiog raphy (TEE) is analysed in patients with suspected embolism and guidelines are proposed for performing echocardiography in this setting. In general, e chocardiography is reliable for diagnosing sources of embolism and this app lies in particular to TEE in the case of atrial, valvular, and aortic abnor malities. However, the method is useful for predicting embolism in a few ca ses only. There is a substantial risk in the event of mobile or protruding thrombi, but screening for these and other markers of thromboembolism seems to be unproductive in most groups of risk patients. Yet, in the presence o f atrial fibrillation, echocardiography may be helpful in defining patients with an otherwise normal heart and low risk of embolism - and in defining the relatively rare patient with a clinically low-risk profile but moderate -to-severe left ventricular systolic dysfunction and a high risk of embolis m. TEE-guided conversion of atrial fibrillation without weeks of preceding anticoagulation may prove useful, after further investigation. The risk of embolism in relation to the size and mobility of valvular vegetations has r emained controversial. In patients with suspected recent embolism, TTE resu lts in less than 5% new therapeutic consequences. In those with a normal TT E, the yield of TEE seems to be equally low. We therefore recommend a selec tive strategy: TTE and TEE can be omitted when a cardiac source of embolism appears from the clinical setting and in most patients with an obvious pre disposition to cerebrovascular disease. However, in the latter cases TTE sh ould be performed if indicated by the clinical situation, e.g. in the prese nce of fever and murmur. TTE is also recommended when there are no obvious markers of primary vascular disease. To preclude very rare sources of embol ism (e.g. atrial thrombi despite sinus rhythm), supplementary TEE is recomm ended in younger patients in whom primary vascular disease is very unlikely . The diagnosis by TEE of common conditions such as atrial septal aneurysms and patent foremen ovale cannot, however, be taken as proof of the mechani sm of a systemic arterial occlusive event; thus it is difficult to change t herapy on the basis of such diagnoses.