45 results about "Atrial tachycardia" patented technology

An embodiment of the invention includes a surgical device for coagulating soft tissue such as atrial tissue in the treatment of atrial fibrillation, atrial flutter, and atrial tachycardia; tendon or ligament shrinkage; or articular cartilage removal. The surgical device integrates a suction mechanism with the coagulation mechanism improving the lesion creation capabilities of the device. The surgical device comprises an elongate member having an insulative covering attached about conductive elements capable of coagulating soft tissue when radiofrequency or direct current energy is transmitted to the conductive elements. Openings through the insulative covering expose regions of the conductive elements and are coupled to lumens in the elongate member which are routed to a vacuum source. Suction causes the soft tissue to actively engage the opening thus the integrated, exposed conductive elements to facilitate the coagulation process and ensure the lesions created are consistent, continuous, and transmural. The embodiments of the invention can also incorporate cooling mechanisms associated with the conductive elements and coupled to a fluid source to passively transport fluid along the contacted soft tissue surface to cool thus pushing the maximum temperature deeper into tissue.

An embodiment of the invention includes a surgical device for coagulating soft tissue such as atrial tissue in the treatment of atrial fibrillation, atrial flutter, and atrial tachycardia. The surgical device can include at least one elongate member comprising conductive elements adapted to coagulate soft tissue when radiofrequency or direct current energy is transmitted to the conductive elements. Openings through said conductive elements are routed through lumens in the elongate member to a vacuum source to actively engage the soft tissue surface intended to coagulate into intimate contact with the conductive elements to facilitate the coagulation process and ensure the lesions created are consistent, contiguous, and transmural. The embodiments of the invention can also incorporate cooling openings positioned near the conductive elements and coupled with a vacuum source or an injection source to transport fluid through the cooling openings causing the soft tissue surface to cool thus pushing the maximum temperature deeper into tissue. The embodiments of the invention can also incorporate features to tunnel between anatomic structures or dissect around the desired tissue surface to coagulate thereby enabling less invasive positioning of the soft tissue coagulating device and ensuring reliable and consistent heating of the soft tissue.

An implantable cardiac stimulation device discriminates and treats accelerated atrial arrhythmias of a patient's heart. The device includes a sensing circuit that senses cardiac activity of one of the patient's atria to provide an atrial activity signal, a detector that detects an accelerated atrial arrhythmia of the patient's heart, and a classifying circuit that measures relative correspondence between successive P waves of the atrial activity signal to classify the detected accelerated atrial arrhythmia as either atrial tachycardia or atrial fibrillation. A therapy circuit provides anti-tachycardia pacing therapy responsive to a classified atrial tachycardia and defibrillation therapy responsive to a classified atrial fibrillation.

A system and method are provided for developing a database of body surface ECG P-wave maps for classification and localization of left-sided atrial arrhythmias. The system and method include generating and receiving P-wave data in a subject by left atrial pacing or receiving P-wave data in a subject during spontaneously occurring or induced left atrial arrhythmias; computing (e.g. potential or integral) maps of the P-wave data; classifying the maps specific to a left atrial ectopic origin; verifying the classification procedure; averaging the classified maps into mean maps; and storing and accessing the mean maps in the database. The mean maps of the P-wave data in the database can be used to automatically classify and localize P-wave data from a patient obtained during a left atrial arrhythmia such as atrial tachycardia, focal atrial fibrillation, or orthodromic atrioventricular reentrant tachycardia.

Apparatus is provided, which includes an electrode device, configured to be coupled to an atrial site of a subject containing parasympathetic nervous tissue, and a control unit. The control unit is configured to, responsively to a detection of an episode of non-sinus atrial tachycardia, restore normal sinus rhythm (NSR) of the subject, by driving the electrode device to apply a parasympathetic stimulation signal to the atrial site, and configuring the parasympathetic stimulation signal to activate the parasympathetic nervous tissue sufficiently to restore the NSR. Other embodiments are also described.

Techniques for improving the specificity of automatic mode switching (AMS) are provided to prevent inappropriate mode switching and to ensure that mode switching is performed when needed. In one example, improved techniques for calculating a filtered rate interval (FARI) are provided, which help avoid inappropriate mode switching within devices that employ FARI in connection with the determination of the atrial rate. Also, techniques are provided for detecting atrial tachycardia and for distinguishing between a true tachycardia and a false tachycardia (such as pacemaker mediated tachycardia). The techniques described herein for detecting atrial tachycardia and for distinguishing between true and false tachycardia are advantageously employed in connection with AMS but may be used in other circumstances as well. Techniques employed in conjunction with dynamic atrial overdrive (DAO) pacing are also discussed.

Techniques for enabling both preventive overdrive pacing and antitachycardia pacing (ATP) within an implantable device are provided. The device gains the benefits of overdrive pacing for preventing the onset of a tachycardia and, if one nevertheless occurs, ATP is employed to terminate the tachycardia. In particular, a technique is provided for promptly detecting the onset of atrial tachycardia during preventive overdrive pacing based on loss of capture of atrial pacing pulses. A technique is also provided for using detection of loss of capture of atrial or ventricular pacing pulses to trigger automatic switching from overdrive pacing to ATP. A setup technique determines whether to enable the automatic switching from overdrive pacing to ATP within a particular patient. Also, techniques are provided for verifying loss of capture of atrial or ventricular backup pacing pulses and for detecting low amplitude ventricular fibrillation based on loss of capture of ventricular backup pacing pulses.

The invention relates to the use of atrial pacing therapies to treat atrial tachycardia (AT). When an AT episode is detected, an implantable medical device applies an ATP therapy. If the AT episode persists, the ATP therapy may be automatically reapplied at a later time during the course of the same AT episode. In particular, previously used ATP therapies are reapplied when episodic conditions, such as cycle length or cycle regularity, change. Although a particular ATP therapy initially may be unsuccessful in terminating the AT, it may prove successful when the cycle length or regularity of the atrial rhythm changes. As the rhythm slows down, the AT may be more responsive to ATP therapies that were previously unsuccessful. As a result, potentially efficacious ATP therapies can be reapplied to terminate AT episodes, and reduce the number of episodes that require more aggressive termination by painful, atrial shocks.

A method for operating a cardiac pacemaker in which the mode of operation of the pacemaker is altered in response to detecting an episode of atrial tachycardia. In accordance with the invention, the pacemaker's pacing mode is altered in a manner that attempts to maintain hemodynamic stability during the atrial tachycardia. Such a mode switch is particularly applicable to pacemaker patients suffering from some degree of congestive heart failure.

Systems and methods are provided for use by implantable medical devices equipped to deliver multi-site left ventricular (MSLV) pacing. MSLV is associated with a relatively long post-ventricular atrial blanking (PVAB) period that might limit the detection of pathologic rapid organized atrial tachycardias (OAT). In one example, MSLV cardiac resynchronization therapy (CRT) pacing is delivered within a tracking mode. A possible atrial tachycardia is detected based on the atrial rate exceeding an atrial tachycardia assessment rate (ATAR) threshold. The device then switches to single-site LV pacing, thereby effectively shortening the PVAB to detect additional atrial events that might otherwise be obscured, and thereby permitting the device to more reliably distinguish organized atrial tachycardias (such as atrial flutter) from sinus tachycardia. The device may also employ an automatic mode switch (AMS) threshold that is set higher than the ATAR threshold for use in switching from tracking modes to nontracking modes.

A pacemaker is operable in a tracking and a non-tracking mode and has an automatic mode switching function for switching the pacemaker into the non-tracking mode of operation in response to the detection of atrial tachycardia. A comparator compares an atrial interval, between detected atrial events, with a predetermined atrial tachycardia limit value and records a tachycardia indication if the interval is less than the atrial tachycardia limit value. The mode switching unit switches the mode of operation to the non-tracking mode if the number of recorded tachycardia indications reaches a predetermined tachycardia count limit. Intervals between other cardiac events detected by the atrial detector or a ventricular detector also are supplied to the comparator wherein they are compared with the atrial tachycardia limit value. The recorded number of tachycardia indications is reduced by one if at least one of these additional intervals, during a pacemaker interval between two consecutive ventricular stimulations or between two consecutive R-wave detections, is longer than the tachycardia limit value.

An intelligent electrocardiogram data classification method based on voting ensemble learning in the invention is characterized by being realized through the following steps: a) carrying out data preprocessing; b) establishing a logistic regression model; c) establishing a decision tree model; d) establishing a support vector machine; e) establishing a naive Bayesian model; f) establishing a neuron model; g) establishing a k proximity model; and h) carrying out model integration. Finally, a model with the accuracy of not less than 80% is obtained, and the effect of the model is better than theeffect of the single model established in the steps b) to g). According to the intelligent electrocardiogram data classification method, enough data are firstly acquired from ccdd and are divided into a training set and a test set, then various models are established, and the model with accuracy of not less than 80% is finally obtained, thereby realizing intelligent identification and classification of normal, atrial fibrillation, atrial premature beat, accidental atrial premature beat, frequent atrial premature beat, atrial tachycardia and atrial fibrillation accompanied with rapid ventricular rate, and realizing early discovery and early treatment of cardiovascular diseases.

Techniques are provided for controlling the recording of intracardiac electrograms (IEGMs) within an implantable medical device such as a pacemaker, wherein the device is capable of recording different channels of IEGMs in response to different diagnostic triggers. Exemplary triggers include pacemaker-mediated tachycardia; atrial tachycardia, atrial fibrillation, ventricular tachycardia, etc. In one example, the device stores, for each diagnostic trigger, a physician selection of particular IEGMs to be recorded for subsequent review. Then, whenever a trigger is detected, the device senses and records only the particular IEGMs that had been selected by the physician for that particular trigger. The IEGMs are eventually transmitted to an external programmer for review. In this manner, the physician can specify particular IEGMs to be stored in response to particular diagnostic triggers, thereby providing considerable diagnostic flexibility, while also conserving memory. Triggers can be classified as atrial-related or ventricular-related, with appropriate IEGMs stored. Pre-trigger IEGM storage can also be accommodated.