A catheter adapted for mapping and ablating epicardial tissue from the pericardial cavity includes a catheter body and an electrode assembly that has a tip section and a loop member lying generally within a plane, wherein the tip section includes an ablation electrode exposed on one side of the loop member and an insulation member exposed on an opposite side of the loop member. The catheter also includes a intermediate section between the catheter body and the electrode assembly, wherein the intermediate deflects the loop member and the tip section bi-directionally within the same plane. So arranged, the catheter can be safely maneuvered in the pericardial sac and swept in a side to side motion over the epicardium with the ablation electrode reliably facing and making contact with the epicardium. The tip section can include a balloon that is inflatable to push away surrounding pericardial tissue. The catheter may further include an injection needle whose distal end can extend outside of the tip section to puncture epicardial tissue. A lumen in the injection needle allows for delivery to agents directly to the punctured tissue and thermocouple wires can be carried in the lumen for temperature sensing at the treatment site.