The catheter maze procedure for the treatment of chronic atrial fibrillation requires the creation of transmural, continuous linear atrial lesions. Attempts to drag a conventional radiofrequency ablation catheter across the atria in clinical as well as experimental studies have resulted in discontinuous lesions. Continuous linear lesions have been most difficult to create in trabeculated atrial muscle. Lesion discontinuities or gaps have resulted in reentrant atrial tachyarrhythmias in patients after ablation. We have explored the use of a linear laser catheter for the creation of continuous atrial lesions. A linear laser system may offer a number of potential advantages over conventional radiofrequency catheter ablation: (1) the laser diffuser …