Abstract: A cardiac probe employs a dynamic mounting element that supports one or more electrodes at its distal end in relatively constant surface contact against the expanding and contact endocardial surface.

Abstract: A coaxial antenna assembly conducts a pressurized medium for absorbing heat along the coaxial cable.

Abstract: A method and apparatus for contacting heart valve tissue with a catheter tip electrode adapted for atrioventricular (AV) node mapping and modification is provided. The tip is conformed to rest stably and comfortably on a cardiac valve such as the mitral or tricuspid valve. The tip has a peanut shape consisting of two electrode lobes joined by a narrower connecting piece. The tip rests on the valve at the connecting piece and is secured by the adjoining lobes. The connecting piece itself may either be insulating or electrically conductive. The catheter may also include standard mapping and/or pacing electrodes. The catheter may further include a steering mechanism for positioning the catheter at various treatment sites in the heart.

Abstract: A catheter has an electrode tip assembly that is bendable at the selection of the user in two different directions. The electrode tip assembly assumes a different predetermined curve configuration when bent in the two direction.

Abstract: A reinforcing sleeve encloses a bendable electrode tip assembly for a catheter. The reinforcing sleeve is flexible enough to accommodate the bending movement desired for the electrode tip assembly. Still, the reinforcing sleeve provides added strength and resistance against wear and tear during repeated bending operations. The reinforcing sleeve also holds associated steering wires and electrical conducting wires in close intimate contact against the interior support wire of the electrode tip assembly. The intimate contact prevents kinking and chafing of the steering wires and electrical conducting wires during bending operations.

Abstract: A steering mechanism including a steering shaft coupled to a controller which includes a handle and apparatus for manipulating the distal end of the steering shaft. The steering shaft includes a flexible coiled spring having a lead spring fixed in position with respect to a distal end thereof in the distal end of the steering shaft. One or more steering wires is affixed at the distal ends thereof to the lead spring. The steering wires extend through the steering shaft to the controller, and the steering apparatus of the controller is used to place tension on one or both of the steering wires. The attachment of the distal ends of the steering wires to the lead spring may be opposite one another or may be offset for providing greater maneuverability.

Abstract: The apparatus comprises a probe having a tip portion, a first electrode mounted on a terminal free end of the tip portion and a second electrode spaced along the tip portion from the first electrode for supplying a reference potential. The probe is constructed so as to hold the first electrode in contact with tissue of an in vivo beating heart with a positive pressure without causing macroscopic damage to the heart tissue while orienting the probe such that the second electrode is spaced from the heart tissue.A stylet is retractably mounted within the probe, for allowing a physician to maneuver the probe through a vein or the like. Once the probe is in position, it may be replaced by a probe of a different shape. The probe may also be retracted while being inserted, for preventing internal injury to the patient. The stylet may have a noncircular cross-section for restricting directions in which it can bend.