Abstract: A catheter which may be configured as a loop during an ablation procedure, and a method of use for such a catheter, are disclosed. According to one aspect of the present invention, an ablation catheter includes a flexible distal member arranged to inserted into a first vessel in the body of a patient, and an elongated flexible tubular member with a distal portion which is coupled to a proximal portion of the flexible distal member. The elongated flexible tubular member has a flexibility that is greater than or equal to the flexibility of the flexible distal member. The catheter also includes a transmission line which is at least partially disposed within the elongated flexible tubular member. A proximal end of the transmission line is suitable for connection to an electromagnetic energy source. The catheter further includes a transducer that is coupled to the transmission line, and is arranged to generate an electric field sufficiently strong to cause tissue ablation.

Abstract: An ablation catheter includes an elongated flexible tubular member adapted to be inserted into a vessel in the body of a patient. A transmission line is disposed within the tubular member and a transducer is coupled to the transmission line for generating an electric field sufficiently strong to cause tissue ablation. A shape memory wire is positioned at a distal portion of the catheter adjacent the transducer to facilitate straightening the catheter tip after use. In one preferred embodiment, the shape memory wire may a flat wire which is formed from copper beryllium, a steel alloy, or nickel titanium. In another embodiment, the transmission line of the catheter is a coaxial cable, and the transducer is a helical antenna coil that is adapted to radiate electromagnetic energy in the microwave frequency range. In yet another embodiment, the shape memory wire is positioned within the antenna coil. Methods for manufacturing and using such ablation catheters are also described.

Abstract: An ablation catheter with an anchoring tip extension includes an elongated flexible tubular member adapted to be inserted into a vessel in the body of a patient. A transmission line is disposed within the tubular member, and a transducer is coupled to the transmission line for generating an electric field sufficiently strong to cause tissue ablation. An anchoring tip extension, which is located at the distal end of the catheter, lodges into the wall of a cardiac chamber and serves to anchor the catheter both during an ablation procedure and during the process of conforming the catheter to the wall. In one preferred embodiment, the catheter includes a shape memory wire. In another embodiment, the transmission line of the catheter is a co-axial cable, and the transducer is a helical antenna coil that is adapted to radiate electromagnetic energy in the microwave frequency range. Methods for manufacturing and using such ablation catheters are also described.