A catheter body of a catheter assembly includes a proximal portion, an intermediate portion extending from the proximal portion, a distal portion extending from the intermediate portion, and a locating device including a distal tip extending from the distal portion of the catheter body. The intermediate portion defines a longitudinal axis and the distal portion forms a loop including one or more loop segments formed around a central loop axis. The central loop axis is substantially parallel with the longitudinal axis and the one or more loop segments include at least one ablation electrode coupled thereto and adapted to create a lesion, the lesion electrically isolating a vessel from a chamber for treatment of a cardiac arrhythmia. The distal tip of the locating device is substantially parallel with the central loop axis.