[Echocardiogram in atrial fibrillation].

The echocardiogram should be performed in the patients with atrial fibrillation to detect cardiac structurally abnormality and assess left ventricular systolic and diastolic functions. Parameters that reflect left atrium (LA) size such as LA dimension and LA volume have been proposed as predictors of success of the radiofrequency catheter ablation. The transthoracic echocardiogram can provide useful information to guide the management of atrial fibrillation, but cannot exclude thrombus in the left atrial appendage (LAA). The transesophageal echocardiography must be used to rule out intra LA thrombus especially prior to cardioversion and the radiofrequency catheter ablation. The smoke-like echo and sludge in the LA or LAA and the decreased LAA flow velocity are associated with high risk for LA thrombus.