Acknowledging the dimensions and anatomical variations of the pulmonary veins is important when planning pulmonary vein isolation, which contributes to improving the outcome of the intervention.3D TEE is an alternative tool to visualize the pulmonary veins before pulmonary vein isolation because it can evaluate relevant diameters in areas of the pulmonary veins, and their spatial relationship to surrounding structures.Conventional 2D echocardiography is not suitable for displaying and measuring most of the specific pulmonary veins parameters that affect the pulmonary veins isolation outcome.However, the 3D method can overtake the 2D limitations.3D TEE could replace the CT in the visualization of pulmonary veins with the advantages that it requires less time, the cost is lower and it doesn't expose the patient to radiation.Before beginning the image acquisition, position the patient in a left lateral decubitus position.Set up echocardiographic and oxygen saturation monitoring.For visualization of the left pulmonary veins, insert the probe into the esophagus at approximately 30-40 cm from the front teeth and use 2D image acquisition at 20-45
