Catheter for RF ablation with cooled electrode and method

Claim 1

A method for creating a lesion in tissue having blood therein and having a surface by the use of an impervious metal conducting electrode having a chamber therein comprising bringing the electrode into contact with the surface of the tissue to form an electrode-surface interface, supplying radio frequency energy at a predetermined power level in excess of 10 watts to the inpervious metal conducting electrode to cause heating of the tissue in the vicinity of the surface contacted by the impervious metal conducting electrode, cooling the impervious metal conducting electrode with a cooling liquid delivered into the chamber so that the temperature in the tissue does not reach a temperature in excess of approximately 95° C. and thereby inhibiting coagulation of blood on the impervious metal conducting electrode and making possible the formation of a wide and deep lesion in the tissue.

Claim 2

A method for creating a lesion in tissue having blood therein and having a surface by the use of an impervious metal conducting electrode having a chamber therein comprising bringing the electrode into contact with the surface of the tissue to form an electrode-surface interface, supplying radio frequency energy at a predetermined power level in excess of 10 watts to the inpervious metal conducting electrode to cause heating of the tissue in the vicinity of the surface contacted by the impervious metal conducting electrode, cooling the impervious metal conducting electrode with a cooling liquid delivered into the chamber so that the temperature in the tissue does not reach a temperature in excess of approximately 95° C. and thereby inhibiting coagulation of blood on the impervious metal conducting electrode and making possible the formation of a wide and deep lesion in the tissue.

Claim 3

A method for controlling the temperature of an energy delivering electrode disposed on an ablation catheter for forming a lesion in tissue in an internal organ having blood therein comprising providing an ablation catheter in the form of a thin, flexible elongate member having disposed at a distal portion thereof at least one imprevious energy delivering electrode having a chamber therein, the catheter having a liquid delivering lumen associated therewith in communication with the chamber and being adapted for intravascular delivery to an internal organ and being in electrical communication with a radio frequency power supply, intravascularly delivering the catheter to an internal organ, delivering radio frequency energy in excess of 10 watts of power from the power supply through the catheter to the impervious energy delivering electrode and into the tissue, selectively delivering a cooling liquid through the lumen of the cathether into the chamber at a desired flow rate and adjusting the flow rate of the cooling liquid through the lumen of the catheter so that a wide and deep lesion is formed in the tissue while inhibiting the coagulation of blood on the electrode.

Claim 4

A method for controlling the temperature of an energy delivering electrode disposed on an ablation catheter for forming a lesion in tissue in an internal organ having blood therein comprising providing an ablation catheter in the form of a thin, flexible elongate member having disposed at a distal portion thereof at least one imprevious energy delivering electrode having a chamber therein, the catheter having a liquid delivering lumen associated therewith in communication with the chamber and being adapted for intravascular delivery to an internal organ and being in electrical communication with a radio frequency power supply, intravascularly delivering the catheter to an internal organ, delivering radio frequency energy in excess of 10 watts of power from the power supply through the catheter to the impervious energy delivering electrode and into the tissue, selectively delivering a cooling liquid through the lumen of the cathether into the chamber at a desired flow rate and adjusting the flow rate of the cooling liquid through the lumen of the catheter so that a wide and deep lesion is formed in the tissue while inhibiting the coagulation of blood on the electrode.

Claim 7

A method for performing an ablation in the myocardium of a heart by utilizing a catheter having a distal extremity with an impervious conductive electrode having a chamber therein mounted thereon comprising introducing the catheter into the heart so that the electrode is in contact with the myocardium, supplying radio frequency energy to the electrode at a power level in excess of 10 watts and supplying a cooling liquid to the chamber of the electrode for cooling the electrode during the time that the radio frequency energy is being supplied to the electrode and withdrawing the cooling liquid after it has cooled the electrode to make possible the formation of a wide and deep lesion in the myocardium while inhibiting the coagulation of blood on the conductive electrode.

Claim 8

A method for performing an ablation in the myocardium of a heart by utilizing a catheter having a distal extremity with an impervious conductive electrode having a chamber therein mounted thereon comprising introducing the catheter into the heart so that the electrode is in contact with the myocardium, supplying radio frequency energy to the electrode at a power level in excess of 10 watts and supplying a cooling liquid to the chamber of the electrode for cooling the electrode during the time that the radio frequency energy is being supplied to the electrode and withdrawing the cooling liquid after it has cooled the electrode to make possible the formation of a wide and deep lesion in the myocardium while inhibiting the coagulation of blood on the conductive electrode.