Abstract: Methods for delivering precise amounts of fluid into cardiac tissue for the purpose of facilitating ablation of the tissue along a desired lesion line. One method injects fluid through a hollow needle. The injected fluid can be a highly conductive fluid injected in conjunction with radiofrequency ablation to create an ablative virtual electrode. The injected conductive fluid can provide deeper and narrower conduction paths and resulting lesions. Radiofrequency ablation can be performed at the same time as the fluid injection, using the injection device as an electrode, or subsequent to the fluid injection, using a separate device. In some methods, the injected fluid is a protective fluid, injected to protect tissue adjacent to the desired lesion line. Fluid delivery can be endocardial, epicardial, and epicardial on a beating heart. The present methods find one use in performing maze procedures to treat atrial fibrillation.

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 method for ablation in which a portion of atrial tissue around the pulmonary veins of the heart is ablated by a first elongated ablation component and a second elongated ablation component movable relative to the first ablation component and having means for magnetically attracting the first and second components toward one another. The magnetic means draw the first and second components toward one another to compress the atrial tissue therebetween, along the length of the first and second components and thereby position the device for ablation of the tissue.

Abstract: A method for ablation in which a portion of atrial tissue around the pulmonary veins of the heart is ablated by a first elongated ablation component and a second elongated ablation component movable relative to the first ablation component and having means for magnetically attracting the first and second components toward one another. The magnetic means draw the first and second components toward one another to compress the atrial tissue therebetween, along the length of the first and second components and thereby position the device for ablation of the tissue.

Abstract: A hemostat-type device for ablative treatment of tissue, particularly for treatment of atrial fibrillation, is constructed with features that provide easy and effective treatment. A swiveling head assembly can allow the jaws to be adjusted in pitch and roll. Malleable jaws can permit curved lesion shapes. A locking detent can secure the jaws in a closed position during the procedure. An illuminated indicator provides confirmation that the device is operating. A fluid delivery system simplifies irrigated ablation procedures.

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 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 catheter body of a catheter assembly includes a proximal portion, an intermediate portion extending from the proximal portion, a distal portion extending from the intermediate portion, and a locating device including a distal tip extending from the distal portion of the catheter body. The intermediate portion defines a longitudinal axis and the distal portion forms a loop including one or more loop segments formed around a central loop axis. The central loop axis is substantially parallel with the longitudinal axis and the one or more loop segments include at least one ablation electrode coupled thereto and adapted to create a lesion, the lesion electrically isolating a vessel from a chamber for treatment of a cardiac arrhythmia. The distal tip of the locating device is substantially parallel with the central loop axis.

Abstract: A device for ablating tissue is provided. The device comprises a conductive element with a channel for irrigating fluid formed therein, which is in contact with a non-conductive microporous interface. All or a portion of the interface may be removable. When the interface is removed, a portion of the conductive element is exposed for use in ablating tissue. Methods of using the device and of removing the interface are also provided.

Abstract: A catheter assembly and method for treatment of cardiac arrhythmia, for example, atrial fibrillation, by electrically isolating a vessel, such as a pulmonary vein, from a chamber, such as the left atrium. The catheter assembly includes a catheter body and at least one electrode. 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 forms a substantially closed loop transverse to the longitudinal axis. The at least one electrode is disposed along the loop. With this configuration, the loop is axially directed into contact with the chamber wall about the vessel ostium. Upon energization, the electrode ablates a continuous lesion pattern about the vessel ostium, thereby electrically isolating the vessel from the chamber.

Abstract: A suction assisted ablation device having a support surface, suction elements disposed adjacent the support surface, at least one electrode and at least one suction conduit is provided. The device may further include fluid openings, which allow fluid to irrigate target tissue and aid in ablation. A method for ablating tissue using suction is also provided.

Abstract: An instrument including an elongated shaft and a non-conductive handle is disclosed. The shaft defines a proximal section and a distal section. The distal section forms an electrically conductive tip. Further, the shaft is adapted to be transitionable from a straight state to a first bent state. The shaft is capable of independently maintaining the distinct shapes associated with the straight state and the first bent state. The handle is rigidly coupled to the proximal section of the shaft. The instrument is useful for epicardial pacing and/or mapping of the heart for temporary pacing on a beating heart, for optimizing the placement of ventricular leads for the treatment of patients with congestive heart failure and ventricular dysynchrony and/or for use in surgical ablation procedures.

Abstract: A method of and a system for treatment of atrial tachyarrhythmias. The system includes a set of hemostats having elongated opposing jaws carrying mechanisms for applying ablation energy along the jaws. The jaws having straight and curved configurations selected to allow arrangement of the jaws of along opposite sides of walls of a patient's atrium. Treatment is accomplished by applying of ablation energy to the walls of a patient's artria to create lines of lesion corresponding generally to incisions employed in a Maze type procedure.

Abstract: An ablation apparatus including a maneuvering mechanism, a conductive element attached to the apparatus, a sensor attached to the apparatus and an output device in communication with the sensor is provided. The sensor senses vibration during the ablation procedure and sends a signal to the output device to reduce power to the conductive element.

Abstract: A catheter assembly and method for treatment of cardiac arrhythmia, for example, atrial fibrillation, by electrically isolating a vessel, such as a pulmonary vein, from a chamber, such as the left atrium. The catheter assembly includes a catheter body and at least one electrode. 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 forms a substantially closed loop transverse to the longitudinal axis. The at least one electrode is disposed along the loop. With this configuration, the loop is axially directed into contact with the chamber wall about the vessel ostium. Upon energization, the electrode ablates a continuous lesion pattern about the vessel ostium, thereby electrically isolating the vessel from the chamber.

Abstract: A method for ablation in which a portion of atrial tissue around the pulmonary veins of the heart is ablated by a first elongated ablation component and a second elongated ablation component movable relative to the first ablation component and having means for magnetically attracting the first and second components toward one another. The magnetic means draw the first and second components toward one another to compress the atrial tissue therebetween, along the length of the first and second components and thereby position the device for ablation of the tissue.

Abstract: A system for monitoring temperature generated by an ablation apparatus on organic tissue is provided. The system comprises a an ablation apparatus operatively adapted to ablate a first side of the tissue, a temperature-sensing pad operatively adapted to sense temperature along a second side of the tissue and an output device in communication with the pad adapted to indicate the temperature of the tissue.

Abstract: A hemostat-type device for ablative treatment of tissue, particularly for treatment of atrial fibrillation, is constructed with features that provide easy and effective treatment. A swiveling head assembly can allow the jaws to be adjusted in pitch and roll. Malleable jaws can permit curved lesion shapes. A locking detent can secure the jaws in a closed position during the procedure. An illuminated indicator provides confirmation that the device is operating. A fluid delivery system simplifies irrigated ablation procedures.

Abstract: A method and system for ablating tissue to provide a desired set of lesions. The system includes an ablation apparatus having an elongated shapeable section carrying a mechanism such as an electrode for applying ablation energy along the shapeable section. The shapeable section includes a member of shape memory material having a memorized configuration. The shapeable section is shaped manually or using fixtures to display a configuration corresponding to one of the desired lesions and is then employed to create the desired lesion. Thereafter the shapeable section is heated to cause it to resume its memorized configuration. Shaping, heating and ablating to create lesions are continued as necessary provide the desired set of lesions. In some embodiments of the invention, heating may be accomplished using heating elements built into the shapeable section.

Abstract: A method of and a system for treatment of atrial tachyarrhythmias. The system includes a set of hemostats having elongated opposing jaws carrying mechanisms for applying ablation energy along the jaws. The jaws having straight and curved configurations selected to allow arrangement of the jaws of along opposite sides of walls of a patient's atrium. Treatment is accomplished by applying of ablation energy to the walls of a patient's artria to create lines of lesion corresponding generally to incisions employed in a Maze type procedure.