An apparatus for localising an electrical field for electroporation of abluminal tissue such as ganglionated plexi is provided comprising a pulsed DC electrical power supply and at least two catheters. Each catheter includes at least one catheter tip and electrode assembly configured for endocardial placement such that the electrodes are positionable at separate endocardial locations and allow development of an electrical field between the electrodes to effect electroporation of the abluminal tissue in the electrical field.
