Abstract: A system and method for creating lesions and assessing their completeness or transmurality. Assessment of transmurality of a lesion is accomplished by monitoring the depolarization signal in a local electrogram taken using electrodes located adjacent the tissue to be ablated. Following onset of application of ablation energy to heart tissue, the local electrogram is measured with electrodes located adjacent tissue to be ablated so that the ablation energy to ablation elements can be selectively reduced or terminated when transmurality is detected.

Abstract: A system and method for creating lesions and assessing their completeness or transmurality. Assessment of transmurality of a lesion is accomplished by monitoring the depolarization signal amplitude in a local electrogram taken using electrodes located adjacent the tissue to be ablated. Following onset of application of ablation energy to heart tissue, the amplitude of a local electrogram measured with electrodes located adjacent tissue to be ablated first gradually drops and then stabilizes, indicating that the tissue being monitored has ceased making any contribution to the sensed electrogram. The amplitude drop and/or the following amplitude plateau may be used alone or together as indicators of transmurality. Detection of a rapid drop in amplitude may be employed as an indicator that the ablation process is proceeding too quickly and may be employed to trigger a reduction in the power of applied ablation energy.

Abstract: A delivery catheter for delivering an intra-bodily medical device to an internal bodily site. The delivery catheter includes an elongated shaft defining a proximal section and a distal section. A delivery lumen is formed by the shaft, extending from the proximal section and terminating at an opening formed proximal the distal section. Finally, a locator is formed by the distal section, and is configured to locate a target site. In one preferred embodiment, the locator is elongated, having a diameter less than that of a remainder of the shaft. In another preferred embodiment, the delivery catheter includes a steering device capable of effectuating a bend both proximal and distal the opening for steering the locator to a target site.

Abstract: A system and method for creating lesions and assessing their completeness or transmurality. Assessment of transmurality of a lesion is accomplished by monitoring the impedance of the tissue to be ablated. Rather than attempting to detect a desired drop or a desired increase impedance, completeness of a lesion is detected in response to the measured impedance remaining at a stable level for a desired period of time, referred to as an impedance plateau. The mechanism for determining transmurality of lesions adjacent individual electrodes or pairs may be used to deactivate individual electrodes or electrode pairs, when the lesions in tissue adjacent these individual electrodes or electrode pairs are complete, to create an essentially uniform lesion along the line of electrodes or electrode pairs, regardless of differences in tissue thickness adjacent the individual electrodes or electrode pairs.

Abstract: A trans-septal guide catheter for providing access through the septum separating a first heart chamber from a second heart chamber that includes an elongated guide catheter body extending between guide catheter proximal and distal ends. A distal segment of the guide catheter is adapted to be inserted through the septum to locate the distal segment of the guide catheter within one of the first heart chamber and the second heart chamber. The catheter body encloses a guide catheter lumen adapted to provide access into the one of the first heart chamber and the second heart chamber through a guide catheter lumen proximal end opening and a guide catheter lumen distal end opening.

Abstract: The present invention relates to fabrication methods and apparatus for irrigating medical catheters. Such catheters include at least one section of standard thermoplastic catheter tubing coupled to a section of porous tubing (e.g., ePTFE and the like). A source of fluid couples to the porous portion of tubing to dispense diverse fluids. The manufacturing technique overcomes the inability of such porous material to liquefy and/or bond to most available adhesives by creating a mechanical-based coupling. One aspect of the present invention involves pre-treatment of a portion of a porous material such as ePTFE; that is, a “pre-imbibing” process is employed wherein the ePTFE is saturated with a solution of solvent and dissolved thermoplastic resin. After the solution evaporates a resin-based interstitial residue provides suitable structure that fuses to adjacent thermoplastic material during application of heat, such as during thermal bonding.

Abstract: An elongated medical device insertable through an access pathway into a body vessel, organ or cavity to locate a therapeutic or diagnostic distal segment of the elongated medical device into alignment with an anatomic feature of interest having a malleable distal segment capable of being manually formed into a shape facilitating such alignment at room temperature. The elongated medical device includes a device body distal to section formed of a malleable material including an elongated, malleable member disposed on or within the device body extending in the direction of the device body axis. The malleable member is formed of a Beta III titanium alloy of the type exhibiting superelastic properties when subjected to strain at a bending strain of less than a set threshold strain and capable of undergoing plastic flow to take a set shape when subjected to a strain of greater than the set threshold at the same temperature.

Abstract: A system and method for creating lesions and assessing their completeness or transmurality. Assessment of transmurality of a lesion is accomplished by monitoring the impedance of the tissue to be ablated. Rather than attempting to detect a desired drop or a desired increase impedance, completeness of a lesion is detected in response to the measured impedance remaining at a stable level for a desired period of time, referred to as an impedance plateau. The mechanism for determining transmurality of lesions adjacent individual electrodes or pairs may be used to deactivate individual electrodes or electrode pairs, when the lesions in tissue adjacent these individual electrodes or electrode pairs are complete, to create an essentially uniform lesion along the line of electrodes or electrode pairs, regardless of differences in tissue thickness adjacent the individual electrodes or electrode pairs.

Abstract: A system and method for creating lesions and assessing their completeness or transmurality. Assessment of transmurality of a lesion is accomplished by monitoring the depolarization signal amplitude in a local electrogram taken using electrodes located adjacent the tissue to be ablated. Following onset of application of ablation energy to heart tissue, the amplitude of a local electrogram measured with electrodes located adjacent tissue to be ablated first gradually drops and then stabilizes, indicating that the tissue being monitored has ceased making any contribution to the sensed electrogram. The amplitude drop and/or the following amplitude plateau may be used alone or together as indicators of transmurality. Detection of a rapid drop in amplitude may be employed as an indicator that the ablation process is proceeding too quickly and may be employed to trigger a reduction in the power of applied ablation energy.

Abstract: A catheter assembly for treatment of cardiac arrhythmia. The catheter assembly includes a catheter body and an ablative energy source. The catheter body includes a proximal portion, an intermediate portion, and a distal portion. The intermediate portion extends from the proximal portion and defines a longitudinal axis. The distal portion extends from the intermediate portion and includes an ablation section and a tip. The ablation section forms a loop defining a diameter greater than an outer dimension of a pulmonary vein ostium. The tip extends distally from the ablation section and is configured to locate a pulmonary vein. Finally, the ablative energy source is associated with the ablation section. With this configuration, upon activation of the energy source, the ablation section ablates a desired lesion pattern. In one preferred embodiment, the ablation section forms a distally decreasing radius helix, whereas the tip includes a relatively linear leader section.

Abstract: A delivery catheter for delivering an intra-bodily medical device to an internal bodily site. The delivery catheter includes an elongated shaft defining a proximal section and a distal section. A delivery lumen is formed by the shaft, extending from the proximal section and terminating at an opening formed proximal the distal section. Finally, a locator is formed by the distal section, and is configured to locate a target site. In one preferred embodiment, the locator is elongated, having a diameter less than that of a remainder of the shaft. In another preferred embodiment, the delivery catheter includes a steering device capable of effectuating a bend both proximal and distal the opening for steering the locator to a target site.

Abstract: A catheter assembly and method for treatment of cardiac arrhythmia. In one preferred embodiment, the catheter assembly includes a catheter body, at least one electrode, and a fluid source. The catheter body includes a proximal portion, an intermediate portion, a distal portion, a first lumen, and an ablation section. The intermediate portion extends from the proximal portion and defines a longitudinal axis. The distal portion extends from the intermediate portion and forms a helix or coil. The first lumen extends from the proximal portion to the distal portion. Finally, the ablation section is formed along the helix of the distal portion and defines a loop transverse to the longitudinal axis. The ablation section is, in one preferred embodiment, comprised of a microporous material in fluid communication with the first lumen so as to irrigate fluid from the first lumen to an exterior surface of the ablation section. The electrode is associated with the ablation section.