716 results about "Atrial fibrillation" patented technology

An abnormally rapid ventricular cardiac rate that results from atrial fibrillation can be reduced by stimulating a vagal nerve of the heart. An apparatus for such stimulation includes a power transmitter that emits a radio frequency signal. A stimulator, implanted in a blood vessel adjacent the vagal nerve, has a pair of electrodes and an electrical circuit thereon. The electrical circuit receives the radio frequency signal and derives an electrical voltage from the energy of that signal. The electrical voltage is applied in the form of pulses to the pair of electrodes, thereby stimulating the vagal nerve. The pattern of that stimulating pulses can be varied in response to characteristics of the atrial fibrillation or the ventricular contractions.

A method is provided, including identifying that a subject is at risk of suffering from atrial fibrillation (AF). Responsively to the identifying, a risk of an occurrence of an episode of the AF is reduced by coupling an electrode device to a site of a subject containing parasympathetic nervous tissue; driving, by a control unit, the electrode device to apply an electrical current to the site not responsively to any physiological parameters sensed by any device directly or indirectly coupled to the control unit; and configuring the current to stimulate autonomic nervous tissue in the site. Other embodiments are also described.

Apparatus and methods for the treatment of atrial fibrillation are described herein where tissue to be ablated may be monitored under direct visualization. Such a system may include a deployment catheter and an attached imaging hood deployable into an expanded configuration. In use, the imaging hood is placed against or adjacent to the tissue to be imaged in a body lumen that is normally filled with an opaque bodily fluid such as blood. A translucent or transparent fluid can be pumped into the imaging hood until the fluid displaces any blood leaving a clear region of tissue to be imaged via an imaging element in the deployment catheter. An ablation probe may be advanced into the contained region where the tissue may be ablated and monitored for changes in color as well as appropriate positioning.

An atrial defibrillator includes a portable, non-implantable housing, a pair of defibrillator pads, a shock generator, and an analyzer. The pads are applied to the outside of a patient's body, and the shock generator delivers a shock to the patient via the pads. The analyzer receives a cardiac signal from the patient, determines from the signal whether the patient is experiencing atrial fibrillation, and enables the shock generator if the patient is experiencing atrial fibrillation. Unlike conventional external atrial defibrillators, such an atrial defibrillator can be used by a layperson in the comfort of a patient's own home. Furthermore, such a defibrillator does not cause the surgery-related problems associated with implantable atrial defibrillators. Moreover, because the patient can choose when to receive a shock, such a defibrillator is less likely to surprise and embarrass the patient than automatic implantable defibrillators are.

Method, system and apparatus to detect, diagnose and treat biological rhythm disorders. In preferred particularly desirable embodiment relating to the real-time detection of heart rhythm disorders, this invention identifies localized sources for complex rhythms including atrial fibrillation to guide the localized application of energy to modify the source and treat the rhythm disorder.

A method for the treatment of a patient for the purpose of lowering blood pressure and/or treating cardiac arrhythmias, particularly atrial fibrillation includes the insertion of an ablation catheter into the lumen of a renal artery. The ablation catheter is equipped with an electrode that can stimulate the wall tissue in the renal artery to help identify the location of a renal nerve. High-frequency stimulation of the renal nerve causes a decrease in the blood pressure of the patient thereby indicating that a renal nerve is nearby. The ablation catheter is used to ablate the renal nerve using radiofrequency, ultrasound, microwave energy or cryogenic cooling. An irrigated ablation catheter may be used to decrease damage to cells in the wall of the lumen of the renal artery other than the renal nerve, such as the endothelial cells.

The present invention relates generally to multifunctional catheters for performing ablation procedures, and more particularly to ablation catheters utilized in the treatment of atrial fibrillation and other cardiac disorders. The present invention eliminates many of the problems associated with previous ablation catheters by providing an ablation treatment not dependent upon continuous lesions.

A noninvasive or minimally invasive treatment of cardiac arrhythmia such as supraventricular and ventricular arrhythmias, specifically atrial fibrillation and ventricular tachycardia, by treating the tissue with heat produced by ultrasound, (including High Intensity Focused Ultrasound or HIFU) intended to have a biological and/or therapeutic effect, so as to interrupt or remodel the electrical substrate in the tissue area that supports arrhythmia.

A method and a system for detection of an arrhythmia, the method comprising determining a number of heart beat intervals; determining an instantaneous heart rate for each of the heart beat intervals; determining the variability of the instantaneous heart rates compared to a mean of the number of instantaneous heart rates; determining a non-linear value that represents the variability of the instantaneous heart rates; and detecting the arrhythmia by comparing the non-linear value with a predetermined threshold.

The present invention relates generally to multifunctional catheters for performing ablation procedures, and more particularly to ablation catheters utilized in the treatment of atrial fibrillation and other cardiac disorders. The present invention eliminates many of the problems associated with previous ablation catheters by providing an ablation treatment not dependent upon continuous lesions.

A plethysmogram signal is sensed from a patient and provided to a programmer device for monitoring the condition of the patient and for optimizing pacing parameters of a cardiac device implanted in the patient. The programmer device analyzes the plethysmogram signal for cardiac performance associated with different pacing parameters. The cardiac performance is indicated by, for example, a pulse amplitude response, a degree of pulsus alternans, or irregularity in the pressure pulses detected in an atrial fibrillation patient. The pacing parameters resulting in the best cardiac performance are selected as the optimum pacing parameters. In one embodiment, the programmer device monitors a Valsalva maneuver performed by a patient. Optimum pacing parameters are derived by analysis of the plethysmogram signals obtained during performance of the Valsalva maneuver while the patient is paced using different pacing parameters.

An ablative apparatus and associated methods that can be used to treat atrial fibrillation and other cardiac arryhythmias by ablating cardiac tissue is disclosed. When the distal end of the apparatus reaches the tissue to be ablated, an ablation probe driven by a transducer is vibrated. Scratching the tissue with abrasive members, the vibrating ablation probe is capable of mechanically ablating tissues. This mechanical ablation may be utilized to penetrate epicardial fat, thereby exposing the underlying myocardium. The ablative apparatus may then be used subject the exposed myocardium to mechanical ablation, cryoablation, ultrasonic ablation, and/or any combination thereof.

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. The device may include a swiveling head assembly that allows the jaws to be adjusted in pitch and/or roll. The device may include a malleable or articulating handle shaft, as well as, malleable or curved rigid jaws that can permit curved lesion shapes. A locking detent can secure the jaws in a closed position during the procedure. The device may include one or more remote actuators making the hemostat-type device useful for minimally invasive procedures.

A heat exchange balloon assembly (11) for cooling the esophagus during heat ablation treatment to the heart is disclosed. The heat exchange balloon assembly includes an inflatable balloon (4) adapted for insertion into the esophagus, provided with an exterior heat-transfer surface and a lumen within the inflatable balloon (4) adapted to carry thermal exchange medium configured such that said heat-transfer surface conducts thermal energy between the esophagus and the lumen. Also disclosed is a heat exchange balloon assembly (11) connected to a temperature controller provided with a means to receive data pertinent to the power supplied to an ablation probe and/or the temperature of the tip of the ablation probe. The device may be used in an ablation system and in a method for treatment of atrial fibrillation.

An apparatus and method for detecting an atrial fibrillation through monitoring the R—R intervals of a patient's QRS complexes. Ratios of the current R—R interval are made to previous R—R intervals. Multiple moving averages are taken of the ratio results. The ratios are compared to a validating threshold and if the particular ratio is within a selected range, a moving average is calculated with inclusion of the present R—R interval. If the ratio is outside the range, a moving average is calculated without inclusion of the current R—R interval. The moving averages are combined and this difference average is compared to a trigger threshold. If the difference average exceeds the threshold, an atrial fibrillation is determined to exist, a memory trigger is provided, and the QRS complex data within a selected period of time about the atrial fibrillation event are recorded and removed from overwrite status in the memory. A reset threshold, differing from the trigger threshold, is used and if the difference average falls below the reset threshold, the method and apparatus are re-enabled to record a new AFIB event.

Transcutaneous electrical and magnetic nerve stimulation devices are disclosed, along with methods of averting imminent medical attacks using energy that is delivered noninvasively by the devices. The attacks comprise asthma attack, epileptic seizure, attacks of migraine headache, transient ischemic attack or stroke, onset of atrial fibrillation, myocardial infarction, onset of ventricular fibrillation or tachycardia, panic attack, and attacks of acute depression. The imminence of an attack is forecasted using grey-box or black-box models as used in control theory. In preferred embodiments of the disclosed methods, a vagus nerve in the neck of a patient is stimulated noninvasively to avert the attack.

Systems and techniques for monitoring cardiac activity. In one aspect, a method includes collecting information describing the variability in heart rate over a series of beats, designating variability at a lower end of physiological values as being largely irrelevant to atrial fibrillation, designating variability in a midrange of physiological values as being indicative of atrial fibrillation, designating variability in an upper range of physiological values as being negatively indicative of atrial fibrillation, and determining a relevance of the variability described in the collection to atrial fibrillation.

Systems and methods to assist in locating the focus of an atrial fibrillation include the association of atrial fibrillation cycle length values and statistics relating thereto with temporal locations on an electrogram of a given electrode, and/or the coordination of electrode locations with respective the spectral analyses of electrogram signals and further parameters and statistics relating thereto. Ablation therapy can proceed under guidance of such information.