Abstract: An electrophysiological ablation catheter comprises a flexible shaft having a circumferential tissue ablation structure and a linear tissue ablation structure at its distal end. By positioning the circumferential tissue ablation structure in a pulmonary vein ostium and the linear tissue ablation structure extending radially from the pulmonary vein ostium toward a second pulmonary vein ostium, lesions around and between the ostium may be formed with a single catheter placement. Repositioning the catheter allows the remaining pulmonary vein ostia and tissue therebetween to be ablated in order to treat atrial fibrillation.