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 ; characterized in that the system further comprises: a tubular connector 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 , 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 , so that, during use of the catheterization system, electrical continuity exists between the electrically conductive fluid passing through the lumen of the tubular connector , 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 ; characterized in that the system further comprises: a tubular connector 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 , 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 , so that, during use of the catheterization system, electrical continuity exists between the electrically conductive fluid passing through the lumen of the tubular connector , the electrically conductive net or sponge and the electrically conductive cable or wire . a tubular connector 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 , 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 , so that, during use of the catheterization system, electrical continuity exists between the electrically conductive fluid passing through the lumen of the tubular connector , the electrically conductive net or sponge and the electrically conductive cable or wire . <EOS>