A system comprising: a catheter including a shaft having a proximal portion and a distal portion, an ablation electrode coupled to the distal portion of the shaft, wherein the ablation electrode comprises a plurality of struts (144a, 144b), mechanically coupled to one another at a plurality of joints forming an open framework to define a plurality of cells, the ablation electrode is radially expandable to an expanded state in which a maximum radial dimension of the ablation electrode is greater than a maximum radial dimension of the distal portion of the shaft, in the expanded state the ablation electrode has greater than 50 percent open area defined by the plurality of cells, and in the expanded state, the ablation electrode is configured to allow blood and irrigation fluid to flow through the open area, and an irrigation element, in the expanded state, the irrigation element is enveloped by the expandable portion of the ablation electrode; a generator in electrical communication with the ablation electrode; and a controller in communication with the generator, the controller including one or more processors and a non-transitory, computer-readable storage medium having stored thereon computer executable instructions for causing the one or more processors to control energy delivered from the generator to the ablation electrode to form, in tissue at a treatment site, a lesion having a maximum depth less than about one half of a maximum width. a catheter including a shaft having a proximal portion and a distal portion, an ablation electrode coupled to the distal portion of the shaft, wherein the ablation electrode comprises a plurality of struts (144a, 144b), mechanically coupled to one another at a plurality of joints forming an open framework to define a plurality of cells, the ablation electrode is radially expandable to an expanded state in which a maximum radial dimension of the ablation electrode is greater than a maximum radial dimension of the distal portion of the shaft, in the expanded state the ablation electrode has greater than 50 percent open area defined by the plurality of cells, and in the expanded state, the ablation electrode is configured to allow blood and irrigation fluid to flow through the open area, and an irrigation element, in the expanded state, the irrigation element is enveloped by the expandable portion of the ablation electrode; a shaft having a proximal portion and a distal portion, an ablation electrode coupled to the distal portion of the shaft, wherein the ablation electrode comprises a plurality of struts (144a, 144b), mechanically coupled to one another at a plurality of joints forming an open framework to define a plurality of cells, the ablation electrode is radially expandable to an expanded state in which a maximum radial dimension of the ablation electrode is greater than a maximum radial dimension of the distal portion of the shaft, in the expanded state the ablation electrode has greater than 50 percent open area defined by the plurality of cells, and in the expanded state, the ablation electrode is configured to allow blood and irrigation fluid to flow through the open area, and the ablation electrode comprises a plurality of struts (144a, 144b), mechanically coupled to one another at a plurality of joints forming an open framework to define a plurality of cells, the ablation electrode is radially expandable to an expanded state in which a maximum radial dimension of the ablation electrode is greater than a maximum radial dimension of the distal portion of the shaft, in the expanded state the ablation electrode has greater than 50 percent open area defined by the plurality of cells, and in the expanded state, the ablation electrode is configured to allow blood and irrigation fluid to flow through the open area, and an irrigation element, in the expanded state, the irrigation element is enveloped by the expandable portion of the ablation electrode; a generator in electrical communication with the ablation electrode; and a controller in communication with the generator, the controller including one or more processors and a non-transitory, computer-readable storage medium having stored thereon computer executable instructions for causing the one or more processors to control energy delivered from the generator to the ablation electrode to form, in tissue at a treatment site, a lesion having a maximum depth less than about one half of a maximum width.