Abstract: A cardiovascular electrode catheter for use in arrhythmia ablation procedures has a dumbbell-shaped large-tip electrode having an annular recess or indentation. The annular recess divides the electrode into a ball-shaped distal portion and a generally cylindrical proximal portion. Both the distal and proximal portions of the electrode have a diameter substantially the same as that of the catheter body. The recess enables the electrode to grip the mitral or tricuspid annulus or the atrial or ventricular myocardial wall to improve ablation procedures.

Abstract: A steerable catheter, which is adapted to be inserted into a body lumen, comprises a symmetrical cylindrical control handle, an elongate tubular catheter body, and a flexible catheter tip having a lumen offset from the axis of the catheter tip. The control handle comprises a housing having a piston chamber at its distal end. A piston is mounted in the piston chamber and is afforded lengthwise movement. The proximal end of the catheter body is fixedly attached to the distal end of the piston. A puller wire made of nickel-titanium alloy having shape memory is attached to the housing and extends through the piston, through and coaxial with the catheter body and into the offset lumen of the catheter tip where it is attached to the wall of the catheter tip. Lengthwise movement of the piston relative to the housing results in deflection of the catheter tip.