Catheter for mapping and/or ablation, and methods of using the same. According to one embodiment, catheter includes a metallic cap having a plurality of apertures and at least one electrode disposed in each aperture of the plurality of apertures. According to another embodiment, the catheter includes a non-conductive cap having a plurality of apertures and at least one electrode disposed in each aperture of the plurality of apertures. Electrodes may be paired, arranged along the length of the cap, or circumferentially arranged on the cap, according to various embodiments. According to a further embodiment, a method for treating a condition of a heart includes placing a catheter inside the heart, mapping a region of the heart using mapping electrodes on the catheter, and ablating using an ablation electrode disposed about the mapping electrodes of the catheter.