Abstract: A catheter uses a steerable outer catheter with an inner catheter rotatable and extendable with respect to the outer catheter. The outer catheter may be positioned within a patient's heart and a portion of the outer catheter may provide movement like that of a windshield wiper by manipulation of a spring. By combining the windshield wiper type movement with the extension and rotation of the inner catheter relative to the outer catheter, a large area within a patient's heart may be readily mapped for conduction tissue and be subjected to laser ablation if appropriate. Various configurations provide flexibility in relatively positioning of windows used to apply laser energy and ring electrodes used to sense conduction tissue. Some embodiments provide only laser ablation (no mapping).