A multi-electrode catheter has a longitudinally extending body with a number of longitudinally extending lumens formed therein and a number of electrode assemblies. Each assembly has an electrode located at an external surface of a caudal section of the body and an electrical conductive surface extending longitudinally within an associated lumen of the number of lumens connected to a cephalad section of the body. The conductive electrical surface forms at least a portion of an internal wall of the associated lumen and is in electrical connection with a different one of the electrodes forming the electrode assemblies.