A catheterization system, comprising: a flexible catheter adapted for insertion into a heart of a patient, having a distal portion and a lumen for passing an electrically conductive fluid therethrough to exit the catheter at the distal portion, the lumen connectable to an irrigation pump to form a fluid communication therewith; a fluid reservoir connected to the lumen of the flexible catheter for supplying the electrically conductive fluid to the catheter; electrocardiogram circuitry connectable to the patient for monitoring electrical activity in the heart, the electrocardiogram circuitry having an input; and an electrode (184, 240); characterized in that the system further comprises: a tubular connector (120, 226) having a metal shell with a lumen filled with an electrically conductive net or sponge configured to assure physical contact with electrically conductive fluid flowing in the lumen of the tubular connector (120, 226), the tubular connector further comprising an electrical connector provided on the metal shell; and an electrically conductive cable or wire for forming an electrical connection between the electrical connector and the electrode (184, 240), so that, during use of the catheterization system, electrical continuity exists between the electrically conductive fluid passing through the lumen of the tubular connector (120, 226), the electrically conductive net or sponge and the electrically conductive cable or wire. a flexible catheter adapted for insertion into a heart of a patient, having a distal portion and a lumen for passing an electrically conductive fluid therethrough to exit the catheter at the distal portion, the lumen connectable to an irrigation pump to form a fluid communication therewith; a fluid reservoir connected to the lumen of the flexible catheter for supplying the electrically conductive fluid to the catheter; electrocardiogram circuitry connectable to the patient for monitoring electrical activity in the heart, the electrocardiogram circuitry having an input; and an electrode (184, 240); characterized in that the system further comprises: a tubular connector (120, 226) having a metal shell with a lumen filled with an electrically conductive net or sponge configured to assure physical contact with electrically conductive fluid flowing in the lumen of the tubular connector (120, 226), the tubular connector further comprising an electrical connector provided on the metal shell; and an electrically conductive cable or wire for forming an electrical connection between the electrical connector and the electrode (184, 240), so that, during use of the catheterization system, electrical continuity exists between the electrically conductive fluid passing through the lumen of the tubular connector (120, 226), the electrically conductive net or sponge and the electrically conductive cable or wire. a tubular connector (120, 226) having a metal shell with a lumen filled with an electrically conductive net or sponge configured to assure physical contact with electrically conductive fluid flowing in the lumen of the tubular connector (120, 226), the tubular connector further comprising an electrical connector provided on the metal shell; and an electrically conductive cable or wire for forming an electrical connection between the electrical connector and the electrode (184, 240), so that, during use of the catheterization system, electrical continuity exists between the electrically conductive fluid passing through the lumen of the tubular connector (120, 226), the electrically conductive net or sponge and the electrically conductive cable or wire.