An ablation catheter is provided for ablating internal tissue of a patient. The catheter includes a distal end that is adapted to be inserted into a body cavity relative to a desired location therein (e.g., within the heart). An ablation electrode is connected relative to the distal end of the catheter for providing ablation energy to patient tissue. A heat sink is provided that is in thermal contact with the ablation electrode. The heat sink, in addition to being in thermal contact with the ablation electrode, is electrically isolated from the ablation electrode. This allows the heat sink to conduct heat away from the ablation electrode without dissipating electrical energy from the electrode. In this regard, the heat sink may prevent build-up of excess heat within the electrode that may result in blood coagulation and/or tissue charring.