Electrophysiological Effects of Long, Linear Atrial Lesions Placed Under Intracardiac Ultrasound Guidance

Background A curative atrial fibrillation procedure will most likely rely on creating transmural linear ablative lesions. However, it is currently unknown whether endocardial radiofrequency lesions can create lines of conduction block. Methods and Results In six pigs, intracardiac echocardiography was used to guide the positioning of multiple coil array catheters to bridge endocardial structures in three right atrial locations: (1) from the crista terminalis to the tricuspid annulus; (2) from the fossa ovalis to the crista terminalis; and (3) from the inferior vena cava to the tricuspid annulus. Once the catheter was positioned, linear lesions were made by radiofrequency energy applied sequentially to each of the four coils. After 15 days, the chest was opened and a 112-electrode epicardial plaque was positioned over the atrial free wall lesion to determine activation patterns. Three lesions were placed in each animal, with a mean procedure time of 47±11 minutes. Once adequate contact was determined by in...