Electrode array catheter

A method for performing an electrophysiology procedure at a target site within a heart chamber comprising the following steps:

• selecting an electrode array catheter having a distal end, movable between constrained and unconstrained conditions, the distal end comprising a tip and an elongate electrode body, which naturally assumes a distally-extending, three-dimensional, coiled, conical shape when the distal end is in the unconstrained condition, said curved shape having one or more curved regions curving substantially more than 360.degree., the one or more curved regions of the electrode body comprising at least four electrodes electrically isolated from one another and arranged in distally-extending, three-dimensional, coiled, conical array when said distal end is in the unconstrained condition;
• steering the distal end into the heart chamber;
• unconstraining the distal end so that the electrode body assumes said curved shape with said curved regions curving substantially more than 360.degree., said electrodes extend over more than about 360.degree. of the electrode body and said tip being free and unattached;
• directing the array of electrodes against the endocardial wall within the heart chamber to the target site by remotely deflecting the distal end within the heart chamber;
• and
• performing a chosen electrophysiology procedure, said distally-extending, three-dimensional, coiled, conical curved shape of the distal end chosen so each said electrode engages the endocardial wall at the target site.

An electrode array catheter, for insertion into a heart chamber for placement of multiple electrodes against the heart chamber wall in the vicinity of a target site, comprising:

• an electrode assembly including a distal end, said distal end comprising:
• an elongate electrode body which naturally assumes a distally-extending, three-dimensional, coiled, generally conical shape when in an unconstrained, deployed position;
• and
• at least four electrodes mounted to the electrode body and positioned over more than about 360.degree. of electrode body, said electrodes being electrically isolated from one another and naturally assuming a distally-extending, three-dimensional, coiled, generally conical array when said distal end is unconstrained, said electrodes distributed along said distal end to be able to contact a portion of the chamber wall surrounding the target site, said portion being substantially less than the entire chamber wall.

An electrode array catheter, for insertion into a heart chamber for placement of multiple electrodes against the heart chamber wall in the vicinity of a target site, comprising:

• an electrode assembly including:
• a distal end having a single elongate, resilient, conformable electrode body;
• and
• a plurality of electrodes distributed along the electrode body so that said electrodes naturally assume an array when said electrode body is unconstrained, said electrodes being distributed along the electrode body so as to be able to contact a limited portion of the chamber wall surrounding the target site;
• a flexible delivery sheath, having a hollow interior, a proximal end and a distal end, the electrode assembly being slidably mounted within the hollow interior of the delivery sheath for movement between a retracted position, at least substantially housed within the hollow interior, and a deployed position, extending from the distal end of the delivery sheath;
• and
• the sheath having a distal tip which acts as an electrode.