Methods and systems for ablating tissue

A tissue ablation system for treating fibrillation in a patient, said catheter comprising:

• a steerable elongate flexible shaft having a proximal end and a distal end;
• a housing coupled to the elongate flexible shaft near the distal end thereof;
• and
• an energy source disposed adjacent the housing, the energy source adapted to emit a beam of energy to ablate tissue and create a conduction block therein, the conduction block blocking aberrant electrical pathways in the tissue so as to reduce or eliminate the fibrillation.

A tissue ablation catheter for treating fibrillation in a patient, said catheter comprising:

• a steerable shaft having a central lumen extending between a proximal end and a distal end thereof;
• an elongate flexible shaft slidably disposed in the lumen, and having a proximal end and a distal end;
• a housing coupled to the elongate flexible shaft near the distal end thereof;
• an energy source disposed adjacent the housing, the energy source adapted to emit a beam of energy to ablate tissue and create a conduction block therein, the conduction block blocking aberrant electrical pathways in the tissue so as to reduce or eliminate the fibrillation,
• wherein steering the shaft directs the energy beam to different regions of the tissue.

A tissue ablation catheter for treating fibrillation in a patient, said catheter comprising:

• a steerable elongate flexible shaft having a proximal end and a distal end;
• a housing coupled to the elongate flexible shaft near the distal end thereof;
• a non-expandable reflector element disposed in the housing;
• and
• an energy source disposed adjacent the housing, the energy source adapted to emit energy, wherein the energy is reflected off the reflector element forming a beam of energy directed to tissue, and wherein the energy beam ablates the tissue and create a conduction block therein, the conduction block blocking aberrant electrical pathways in the tissue so as to reduce or eliminate the fibrillation.

A system for ablating tissue in a patient, said system comprising:

• a steerable elongate flexible shaft having a proximal end, a distal end, and a diameter;
• a housing coupled to the elongate flexible shaft near the distal end thereof, wherein the housing has a length, and a diameter greater than the diameter of the elongate flexible shaft;
• an energy source disposed adjacent the housing, the energy source adapted to emit a beam of energy, wherein the energy beam ablates the tissue and creates a conduction block therein, the conduction block blocking aberrant electrical pathways in the tissue so as to reduce or eliminate fibrillation;
• and
• a sheath having a proximal end and a distal end, wherein the steerable elongate flexible shaft is slidably disposed in the sheath, and wherein a distal region of the sheath is configured to accommodate passage of the housing therethrough when the distal region of the sheath is deflected into a curve.

A method for ablating tissue in a patient as a treatment for fibrillation, said method comprising:

• positioning a transseptal sheath across an atrial septum, the transseptal sheath having a lumen extending therethrough;
• advancing an interventional catheter through the transseptal sheath lumen so that at least a portion of the interventional catheter is disposed in a left atrium of the patient, the interventional catheter comprising an energy source near a distal end thereof;
• locating a target treatment region for ablation;
• steering the interventional catheter within the left atrium so that the energy source is adjacent the target treatment region and so that energy emitted from the energy source is directed toward the target treatment region;
• ablating tissue in the target region with the emitted energy thereby creating a conduction block in the tissue that blocks aberrant electrical pathways in the tissue so as to reduce or eliminate the fibrillation;
• and
• confirming isolation of the target region from the remainder of the atrium.

A method for ablating tissue in a patient as a treatment for fibrillation, said method comprising:

• positioning a transseptal sheath across an atrial septum, the transseptal sheath having a lumen extending therethrough;
• advancing an interventional catheter through the transseptal sheath lumen so that at least a portion of the interventional catheter is disposed in a left atrium of the patient, the interventional catheter comprising an energy source near a distal end thereof;
• locating ostia of the left pulmonary veins;
• defining a first contiguous and lesion path encircling at least one ostium of the left pulmonary veins;
• ablating tissue along the first defined lesion path;
• positioning the interventional catheter adjacent the right pulmonary veins;
• locating ostia of the right pulmonary veins;
• defining a second contiguous lesion path encircling at least one ostium of the right pulmonary veins;
• ablating tissue along the second defined lesion path;
• ablating tissue in a first substantially linear path between the first and the second lesion paths such that the first substantially linear path is contiguous with both the first and second lesion paths, and ablating a second substantially linear path that is contiguous with the first substantially linear path and extends therefrom toward the mitral valve;
• and
• confirming isolation of the left and right pulmonary veins, and
• wherein the first and second lesion paths and the first and second substantially linear paths create a conduction block in the tissue that blocks aberrant electrical pathways in the tissue so as to reduce or eliminate the fibrillation.