An ablation catheter (10) includes an elongate carrier (12). A first loop (14.1) is arranged at or adjacent a distal end of the carrier (12). At least one sensing electrode (40) is carried on the first loop (14.1) for sensing irregular activity in a patient's body. At least one further loop (14.2) is arranged proximally relative to the first loop (14.1) on the carrier (12) in a fixed orientation relative to the first loop (14.1). At least one ablating electrode (42) is carried on the second loop (14.2) for ablating a site of the patient's body where irregular electrical activity occurs. In another form of the invention, the ablation catheter includes a carrier (12) having a loop (14) defined at the distal end, the loop (14) comprising a first arm (18) and a second arm (22), the arms (18, 22) of the loop (14) being at least partly electrically isolated with respect to each other and at least one electrode (16, 20) arranged on each arm (18, 22) of the loop (14). In either form of the invention, an ablating electrode (42) carried on an outer periphery of the carrier (12) may be arranged only partially about the periphery of the carrier (12).
