Linear ablation assembly

Abstract

An intravascular device for the formation of linear lesions which has particular utility in the treatment of atrial fibrillation and flutter. The intravascular device has an outer delivery member with a distal section which has an elongated opening and a support element coextending with the opening. An EP device having a plurality of electrodes on its distal section is slidably disposed within the inner lumen of the delivery member but it is secured by its distal end within the distal extremity of the delivery member at least while in operation. In this manner an axial force in the proximal direction on the proximal extremity of the EP device, which extends out of the patient during the procedure, will cause the distal shaft section of the EP device to arch outwardly out of and away from the distal section of the delivery shaft along an inner side of the curved distal section and engage the surface of the patient's heart chamber. RF electrical energy delivered to the electrodes on the distal shaft section of the EP device will form a linear lesion which terminates the fibrillation or flutter.

Description

[0001]This invention is a continuation-in-part of U.S. patent application Ser. No. 08 / 629,057, entitled LINEAR ABLATION ASSEMBLY, filed Apr. 8, 1996, the disclosure of which is incorporated by reference herein.BACKGROUND OF THE INVENTION[0002]This invention generally relates to the detection and elimination of cardiac arrhythmia and particularly atrial fibrillation.[0003]Atrial fibrillation is the disorganized depolarization of a patient's atrium with little or no effective atrial contraction. This condition may be chronic or intermittent, and it presently affects approximately 2 million or more people in the United States alone. For atrial fibrillation refractory to conventional drug therapy, it has been conventional practice to make incisions in the atrial wall, to surgically segregate the tissue thereof, to discontinue the atrial fibrillation. The atrial segments formed by the surgical segregation are electrically isolated and too small to allow the fibrillation to continue. Howe...

AI Technical Summary

Benefits of technology

[0009]In one presently preferred embodiment, the supporting member of the delivery member is a metallic ribbon which has an elongated flat surface which faces the elongated opening in the distal section of the delivery member. It may be made from high strength materials such as stainless steel, pseudoelastic NiTi alloys in an austenite phase. The support element is preferably manually shaped into a curved or angled condition to facilitate entry of the distal extremity of the assembly within the patient's heart chamber, particularly the right atrium, and the proper positioning of the extended distal section of the EP device against the inner surface of the heart chamber. Additionally, an elongated deflection line may be provided in a wall of the delivery member, for deflecting the distal section of the delivery member into a curved or angled condition.

[0010]The inner radius of the extended distal section of the EP device is controlled by the length of the elongated opening in the delivery member and the distance the EP device is spaced from the support element. The effective length of the elongated opening can be controlled by the longitudinal location of the distal end of a sheath disposed about the exterior of the delivery member. As the distal end of the sheath extends distally, the effective length of the elongated opening in the distal section of the delivery member is shortened and the radius of curvature of the distal section of the EP device is correspondingly decreased.

Problems solved by technology

However, the surgical technique is quite traumatic and is unacceptable to a large fraction of those patient's experiencing atrial fibrillation or flutter.

However, the Avitall device cannot be readily placed within the patient's atrial chamber and provide the necessary contact between the electrodes on the device and the atrial tissue to generate linear lesions of a requisite length when RF electrical energy is emitted from the electrodes.

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