Irrigated ablation electrode assembly having off-center irrigation passageway

An irrigated ablation catheter includes a shaft and an electrode assembly affixed to a distal end of the shaft. The distal electrode assembly includes a manifold and an ablation electrode affixed together and extending along a center axis. The electrode has a distal irrigation passageway extending therethrough to an opening at a distal tip of the electrode. The opening of the irrigation passageway is offset in distance from the center axis, and allows a thermal sensor such as a thermocouple to be located in a sensor cavity in the electrode on or near the center axis. One variation involves providing a pair of distal irrigation passageways through the electrode where both of the openings of the passageways are offset from the center axis. The thermal sensor in this variation is located in the sensor cavity substantially on the center axis.