A magnetically-guided catheter includes a tip positioning magnet in the distal end portion thereof configured to interact with externally applied magnetic fields for magnetically-guided movement. The magnet may be geometrically asymmetric, for example, a C-shape in radial cross-section, so as to allow side-loading of an irrigation fluid lumen and other wire(s) or lines during fabrication. The outer shaft includes a plurality of segments, including a generally soft segment at the distal end thereof for magnetically-guided navigation. The fluid lumen, which extends through the outer shaft, and further extends completely through the magnet for coupling to the ablation electrode irrigation fluid inlet, is constructed so that its mechanical properties (i.e., flexibility) substantially matches that of the outer shaft. The combination of the outer shaft, inner fluid lumen and positioning magnet has interoperability with a broad range of ablation tip assemblies.
