A device for high-resolution mapping and ablating targeted tissue of subject, comprising: an elongate body comprising a proximal end and a distal end; a first high-resolution electrode portion positioned on the elongate body; at least a second electrode portion positioned adjacent the first electrode portion, the first and second electrode portions (30A, 30B) being configured to contact tissue of a subject and deliver radiofrequency energy sufficient to at least partially ablate the tissue; and at least one electrically insulating gap positioned between the first electrode portion and the second electrode portion, the at least one electrically insulating gap comprising a gap width separating the first and second electrode portions (30A, 30B); wherein the first electrode portion is configured to electrically couple to the second electrode portion in series using a filtering element, wherein the filtering element is configured to present a low impedance and the first and second electrode portions are configured to function as a single longer electrode at a frequency used for delivering ablative energy via the first and second electrode portions (30A, 30B); wherein the device is configured to be positioned within targeted tissue of the subject to obtain high-resolution mapping data related to said tissue when ablative energy is not delivered to the first and second electrode portions (30A, 30B); wherein the device is used as a roving device and includes a separate mapping device or system to provide mapping data in tissue regions not adequately covered by said separate mapping system, wherein the separate mapping device or system comprises a plurality of mapping electrodes. an elongate body comprising a proximal end and a distal end; a first high-resolution electrode portion positioned on the elongate body; at least a second electrode portion positioned adjacent the first electrode portion, the first and second electrode portions (30A, 30B) being configured to contact tissue of a subject and deliver radiofrequency energy sufficient to at least partially ablate the tissue; and at least one electrically insulating gap positioned between the first electrode portion and the second electrode portion, the at least one electrically insulating gap comprising a gap width separating the first and second electrode portions (30A, 30B); wherein the first electrode portion is configured to electrically couple to the second electrode portion in series using a filtering element, wherein the filtering element is configured to present a low impedance and the first and second electrode portions are configured to function as a single longer electrode at a frequency used for delivering ablative energy via the first and second electrode portions (30A, 30B); wherein the device is configured to be positioned within targeted tissue of the subject to obtain high-resolution mapping data related to said tissue when ablative energy is not delivered to the first and second electrode portions (30A, 30B); wherein the device is used as a roving device and includes a separate mapping device or system to provide mapping data in tissue regions not adequately covered by said separate mapping system, wherein the separate mapping device or system comprises a plurality of mapping electrodes.