A catheter for sensing electrical events about a selected annulus region of the heart and for treating tissue in the selected annulus region has a handle assembly, and a shaft having a proximal end coupled to the handle assembly. The catheter also has a mapping element provided adjacent its distal end, and an ablation element positioned spaced apart along the shaft from the mapping element. The mapping element is first positioned distally to the desired treatment location in the selected annulus region and the distal location is mapped. The expandable member enclosing the ablation element is inflated and contrast medium injected to determine the orientation of the ablation element with respect to the annulus region. After the target ablation site is determined and the PV potentials verified, the ablation element is activated for therapeutic energy delivery.