48 results about "Ventricular tachyarrhythmia" patented technology

An apparatus and method for treating post-defibrillation electromechanical dissociation ("EMD") or pulseless electrical activity ("PEA"). A first embodiment comprises an implantable defibrillator with the capability of detecting and treating post defibrillation EMD. The stimulator / defibrillator has one or more leads with electrodes and at least one electrode for defibrillation. A sense circuit senses the electrical condition of the heart of the patient. A second sensor senses a parameter correlated to the state of blood flow. The cardiac stimulator / defibrillator detects and terminates ventricular tachyarrhythmia or fibrillation. If the stimulator / defibrillator detects the presence of electrical rhythm in the heart correlated, however, with inadequate blood flow to sustain life (EMD), the device provides an output to stimulate the heart to overcome EMD. The device may also be an external defibrillator. The method for treating the heart to restore blood flow where electromechanical dissociation occurs after termination of a ventricular tachyarrhythmia or ventricular fibrillation comprises identifying electromechanical disassociation after termination of a ventricular tachyarrhythmia or a fibrillation and inducing or re-inducing ventricular fibrillation and subsequently applying defibrillating shocks to terminate the fibrillation.

An external defibrillator includes a detector used to detect a life threatening condition of a patient, a controller operating the defibrillator automatically and a therapy delivery circuit that delivers appropriate therapy. Advantageously a parameter is derived from the cardiac signals sensed in the patient, the parameters being used to differentiate between shockable events such as ventricular tachyarrhythmia and other events such as SVT. The defibrillator is attached to a patient by an attendant and once it is attached, the defibrillator is adapted to monitor the patient and when a life threatening condition is detected, to apply therapy automatically, i.e., without any involvement by the patient or the attendant.

A system comprising an implantable medical device (IMD). The IMD includes an implantable sensor operable to produce an electrical signal representative of mechanical activity of a heart of a subject and a controller circuit coupled to the sensor. The IMD also includes a heart sound sensor interface circuit to produce a heart sound signal, a tachyarrhythmia detector, and a controller circuit. The controller circuit includes a hemodynamic stability assessment module configured to determine that at least one episode of ventricular tachyarrhythmia is detected in a subject and obtain a measurement of hemodynamic stability of the ventricular tachyarrhythmia from the heart sound signal.

An apparatus and method for treating post-defibrillation electromechanical dissociation ("EMD"). A first embodiment comprises an implantable defibrillator, which may include cardioversion and pacemaker capabilities, which has the capability of detecting and treating post defibrillation EMD. The stimulator / defibrillator has one or more leads with electrodes. At least one electrode for defibrillation may be an endocardial or epicardial electrode or other suitable defibrillation electrode. A sense circuit senses the electrical condition of the heart of the patient. A hemodynamic sensor senses a parameter correlated to the state of blood flow. The cardiac stimulator / defibrillator detects ventricular tachyarrhythmia including fibrillation and terminates ventricular tachyarrhythmia. After termination of the ventricular tachyarrhythmia, the stimulator / defibrillator can detect the presence of electrical rhythm in the heart correlated, however, with inadequate blood flow to sustain life. Under such conditions, the device provides an output to stimulate the heart to overcome electromechanical dissociation and restore adequate blood flow. The device may also be an external therapy device, as part of, or in conjunction with an external defibrillator. The method for treating the heart to restore blood flow where electromechanical dissociation occurs after termination of a ventricular tachyarrhythmia or ventricular fibrillation comprises identifying electromechanical disassociation after termination of a ventricular tachyarrhythmia or a fibrillation and providing electrical therapy, the therapy comprising a series of packets of electrical pulses.

In an IMD, when tachyarrhythmia detection criterion are satisfied or a high intrinsic heart rate is detected, a peak amplitude detection circuit is enabled to detect the peak amplitude of the cardiac signal of interest, i.e., the P-wave in the case of atrial tachyarrhythmias and the R-wave in case of ventricular tachyarrhythmias. Peak amplitude data is accumulated for subsequent use in setting sensing thresholds and / or gain of a sense amplifier to reduce undersensing of lower amplitude cardiac signals during such tachyarrhythmias.

Cardiac systems and methods provide for discriminating between supraventricular tachyarrhythmia and ventricular tachyarrhythmia based on a determination that the patient's supraventricular rhythm exhibits rate dependency. One approach involves determining if a patient's supraventricular rhythm exhibits rate dependent morphology. If the patient's supraventricular rhythm is determined to exhibit rate dependent morphology, an implantable device classifies a detected tachyarrhythmia episode based on one or more templates selected from a plurality of rate-indexed templates stored in the device. Determining if the supraventricular rhythm exhibits rate dependent morphology may also include determining one or more rates at which the rate dependent morphology occurs.

A device for classifying of supraventricular tachyarrhythmia (SVT) from ventricular tachyarrhythmia (VT) comprising means for providing a template signal and a test signal originated from an electrogram, the template signal and the test signal comprising samples, means for transforming at least the test signal resulting in a representation of the test signal where the sample values of the signal take integers, means for determining a correlation between the template signal and the test signal and means for classifying of SVT from ventricular VT based on the correlation.

In a method and implantable medical device for ventricular tachyarrhythmia detection and classification, upon detection of a ventricular tachyarrhythmia based on an electrocardiogram signal, cardiogenic impedance data representative of ventricular volume dynamics are collected and used for classifying the detected tachyarrhythmia as stable or unstable. In the latter case but typically not in the former case, defibrillation shocks or other forms of therapy are applied to combat the unstable ventricular tachyarrhythmia.

A system and method for selectively treating a ventricular tachycardia based on sensed atrial and ventricular intervals from the patient's heart. A detection window of the ten most recent atrial and ventricular intervals are analyzed for the occurrence of either tachycardia or fibrillation. When a majority of the sensed intervals are satisfied, the apparatus starts a duration time interval. Ventricular intervals and atrial intervals are compare, ventricular interval greater than the atrial interval by a bias factor the system delivers tachycardia therapy to the heart. Alternatively, the method withholds tachycardia therapy to the heart when the atrial rate is classified as atrial fibrillation and the ventricular response is unstable.

The present invention provides novel compounds of Formula I and salts, hydrates, solvates, complexes, and prodrugs thereof. The present invention further provides methods for synthesizing compounds of Formula I. The invention additionally provides pharmaceutical compositions comprising the compounds of Formula I and methods of using the pharmaceutical compositions of Formula I to treat and prevent disorders and diseases associated with the RyR receptors that regulate calcium channel functioning in cells. Such disorders and diseases include, by way of example only, cardiac disorders and diseases, skeletal muscular disorders and diseases, cognitive disorders and diseases, malignant hyperthermia, diabetes, and sudden infant death syndrome. Cardiac disorder and diseases include, but are not limited to, irregular heartbeat disorders and diseases; exercise-induced irregular heartbeat disorders and diseases; sudden cardiac death; exercise-induced sudden cardiac death; congestive heart failure; chronic obstructive pulmonary disease; and high blood pressure. Irregular heartbeat disorders and diseases include and exercise-induced irregular heartbeat disorders and diseases include, but are not limited to, atrial and ventricular arrhythmia; atrial and ventricular fibrillation; atrial and ventricular tachyarrhythmia; atrial and ventricular tachycardia; catecholaminergic polymorphic ventricular tachycardia (CPVT); and exercise-induced variants thereof. Skeletal muscular disorder and diseases include, but are not limited to, skeletal muscle fatigue, exercise-induced skeletal muscle fatigue, muscular dystrophy, bladder disorders, and incontinence. Cognitive disorders and diseases include, but are not limited to, Alzheimer's Disease, forms of memory loss, and age-dependent memory loss.

A Fast Fourier Transform (FFT) converts time-varying event waveforms into the frequency domain waveforms to thereby decompose the events into their spectral components, which are analyzed to distinguish R-waves from T-waves. In some embodiments, the FFT is only activated if a ventricular tachyarrhythmia is already indicated. For example, an initial ventricular rate may be derived from a ventricular IEGM based on all events detected therein. The initial ventricular rate is compared against one or more thresholds representative of ventricular tachycardia (VT) and / or ventricular fibrillation (VF) to determine if VT / VF is indicated. If so, the FFT is activated to distinguish R-waves from T-waves and, in particular, to detect and eliminate T-wave oversensing. Then, the ventricular rate is re-determined based only on the rate of true R-waves. Therapy is delivered if VT / VF is still detected.

Provided herein are methods that include (i) determining a level of soluble ST2 in a biological sample from a subject, (i) comparing the level of soluble ST2 in the biological sample to a reference level of soluble ST2 (e.g., a level of soluble ST2 in the subject at an earlier time point), and (iii) selecting, implanting, replacing, or reprogramming an implanted cardiac device, e.g., an ICD, CRT, or CRT-D device, for a subject having an elevated level of soluble ST2 in the biological sample compared to the reference level of soluble ST2, or selecting a subject for participation in, or stratifying a subject participating in, a clinical study of a treatment for reducing the risk of a ventricular tachyarrhythmia (VTA) event. Also provided are methods for evaluating the risk of a VTA event in a subject. Also provided are kits for performing any of these methods.

The present invention provides novel compounds of Formula I and salts, hydrates, solvates, complexes, and prodrugs thereof. The present invention further provides methods for synthesizing compounds of Formula I. The invention additionally provides pharmaceutical compositions comprising the compounds of Formula I and methods of using the pharmaceutical compositions of Formula I to treat and prevent disorders and diseases associated with the RyR receptors that regulate calcium channel functioning in cells. Such disorders and diseases include, by way of example only, cardiac disorders and diseases, skeletal muscular disorders and diseases, cognitive disorders and diseases, malignant hyperthermia, diabetes, and sudden infant death syndrome. Cardiac disorder and diseases include, but are not limited to, irregular heartbeat disorders and diseases; exercise-induced irregular heartbeat disorders and diseases; sudden cardiac death; exercise-induced sudden cardiac death; congestive heart failure; chronic obstructive pulmonary disease; and high blood pressure. Irregular heartbeat disorders and diseases include and exercise-induced irregular heartbeat disorders and diseases include, but are not limited to, atrial and ventricular arrhythmia; atrial and ventricular fibrillation; atrial and ventricular tachyarrhythmia; atrial and ventricular tachycardia; catecholaminergic polymorphic ventricular tachycardia (CPVT); and exercise-induced variants thereof. Skeletal muscular disorder and diseases include, but are not limited to, skeletal muscle fatigue, exercise-induced skeletal muscle fatigue, muscular dystrophy, bladder disorders, and incontinence. Cognitive disorders and diseases include, but are not limited to, Alzheimer's Disease, forms of memory loss, and age-dependent memory loss.

It has been determined that certain dual-chambered cardiac stimulators may operate in a region in which an atrial pacing event may obscure the detection of a ventricular tachyarrhythmia. Various exemplary techniques may be used to improve the ability of dual-chamber cardiac stimulators to detect such ventricular events. In accordance with one technique, it is determined whether a ventricular event should be classified as a ventricular tachyarrhythmia. If not, the VA interval is restarted as usual. However, if the ventricular event may be classified as a ventricular tachyarrhythmia, it is determined whether the ventricular event falls within the region in which an atrial pacing event may obscure its detection. If not, then the VA interval is restarted as usual. However, if the ventricular event falls within this region, the VA interval is restarted with the VT rate detection boundary. This has the effect of lengthening the VA interval and the AA interval in this region so that atrial pacing events will not obscure the sensing and treatment of ventricular tachyarrhythmias in the region.

An apparatus and method for treating post-defibrillation electromechanical dissociation ("EMD"). A first embodiment comprises an implantable defibrillator, which may include cardioversion and pacemaker capabilities, which has the capability of detecting and treating post defibrillation EMD. The stimulator / defibrillator has one or more leads with electrodes. At least one electrode for defibrillation may be an endocardial or epicardial electrode or other suitable defibrillation electrode. A sense circuit senses the electrical condition of the heart of the patient. A hemodynamic sensor senses a parameter correlated to the state of blood flow. The cardiac stimulator / defibrillator detects ventricular tachyarrhythmia including fibrillation and terminates ventricular tachyarrhythmia. After termination of the ventricular tachyarrhythmia, the stimulator / defibrillator can detect the presence of electrical rhythm in the heart correlated, however, with inadequate blood flow to sustain life. Under such conditions, the device provides an output to stimulate the heart to overcome electromechanical dissociation and restore adequate blood flow. The device may also be an external therapy device, as part of, or in conjunction with an external defibrillator. The method for treating the heart to restore blood flow where electromechanical dissociation occurs after termination of a ventricular tachyarrhythmia or ventricular fibrillation comprises identifying electromechanical disassociation after termination of a ventricular tachyarrhythmia or a fibrillation and providing electrical therapy, the therapy comprising a series of packets of electrical pulses.

A system comprising an implantable medical device (IMD). The IMD includes an implantable sensor operable to produce an electrical signal representative of mechanical activity of a heart of a subject and a controller circuit coupled to the sensor. The IMD also includes a heart sound sensor interface circuit to produce a heart sound signal, a tachyarrhythmia detector, and a controller circuit. The controller circuit includes a hemodynamic stability assessment module configured to determine that at least one episode of ventricular tachyarrhythmia is detected in a subject and obtain a measurement of hemodynamic stability of the ventricular tachyarrhythmia from the heart sound signal.

A system and method for selectively treating a ventricular tachycardia based on sensed atrial and ventricular intervals from the patient's heart. A detection window of the ten most recent atrial and ventricular intervals are analyzed for the occurrence of either tachycardia or fibrillation. When a majority of the sensed intervals are satisfied, the apparatus starts a duration time interval. Ventricular intervals and atrial intervals are compare, ventricular interval greater than the atrial interval by a bias factor the system delivers tachycardia therapy to the heart. Alternatively, the method withholds tachycardia therapy to the heart when the atrial rate is classified as atrial fibrillation and the ventricular response is unstable.

An implantable cardiac stimulation device classifies ventricular tachyarrhythmias as either a ventricular tachycardia or ventricular fibrillation and applies appropriate therapy. The device include sensing circuits that provide right and left ventricular electrogram signals, a detector that detects an accelerated ventricular arrhythmia, and a classifying circuit that measures relative correspondence between the right and left ventricular electrogram signals to classify a detected accelerated ventricular arrhythmia as either ventricular tachycardia or ventricular fibrillation. A therapy circuit is responsive to the classifying circuit and applies appropriate therapy to the heart based upon the tachyarrhythmia classification.

A method employable during a tachycardia-tachyarrhythmia condition in a person for detecting, verifying and distinguishing ventricular and supra-ventricular tachyarrhythmias, including ventricular fibrillation, including (a) confirming the presence of a tachyarrhythmia heart rate, (b) on such confirmation, collecting time-frame-simultaneous ECG and heart-sound information, (c) following such collecting, choosing selected ECG time-span, and heart-sound intensity, data, and (d) utilizing the chosen, selected ECG time-span, and heart-sound intensity, data, characterizing the defined condition as resulting from one of (a) supra-ventricular tachyarrhythmia, (b) ventricular tachyarrhythmia, and (c) ventricular fibrillation.

This document describes systems, devices, and methods that use multiple morphology templates for discriminating between rhythms, such as supraventricular tachyarrhythmias (SVTs) and ventricular tachyarrhythmias (VTs), for delivering a countershock in response to a VT episode, but withholding delivery of such a countershock in response to an SVT episode. In certain examples, the particular morphology used for storing morphological features is selected at least in part using a sensor-indicated activity level of a subject, or a metabolic need of the subject.

It has been determined that certain dual-chambered cardiac stimulators may operate in a region in which an atrial pacing event may obscure the detection of a ventricular tachyarrhythmia. Various exemplary techniques may be used to improve the ability of dual-chamber cardiac stimulators to detect such ventricular events. In accordance with one technique, it is determined whether a ventricular event should be classified as a ventricular tachyarrhythmia. If not, the VA interval is restarted as usual. However, if the ventricular event may be classified as a ventricular tachyarrhythmia, it is determined whether the ventricular event falls within the region in which an atrial pacing event may obscure its detection. If not, then the VA interval is restarted as usual. However, if the ventricular event falls within this region, the VA interval is restarted with the VT rate detection boundary. This has the effect of lengthening the VA interval and the AA interval in this region so that atrial pacing events will not obscure the sensing and treatment of ventricular tachyarrhythmias in the region.

The disclosure describes techniques for delivering electrical stimulation to decrease the ventricular rate response during an atrial tachyarrhythmia, such as atrial fibrillation. AV nodal stimulation is employed during an atrial tachyarrhythmia episode with rapid ventricular conduction to distinguish ventricular tachyarrhythmia from supraventricular tachycardia and thereby prevent delivering inappropriate therapy to a patient.

The disclosure describes techniques for delivering vagal stimulation to decrease the ventricular rate response during an atrial tachyarrhythmia, such as atrial fibrillation. Decreasing the ventricular rate response during an atrial tachyarrhythmia may facilitate increased ventricular pacing for cardiac resynchronization therapy (CRT), and may also reduce the likelihood of inappropriately detecting a ventricular tachyarrhythmia during the atrial tachyarrhythmia. Furthermore, the vagal stimulation may augment vagal tone, which may facilitate long term left ventricular reverse remodeling and decrease atrial and ventricular arrhythmic burden in heart failure patients. An example system that delivers CRT comprises a processor that detects an atrial tachyarrhythmia in one or more atria of the heart, and monitors at least one of a ventricular rate or degree of ventricular pacing subsequent to the detected atrial arrhythmia. The processor controls a stimulation generator to deliver vagal stimulation based on the least one of a ventricular rate or degree of ventricular pacing.

The subject invention pertains to novel compounds (and salts thereof), and compositions comprising the compounds, for the treatment of cardiac arrhythmias. The subject invention further concerns methods of making the novel compounds. The novel compounds are rapidly metabolized analogs of amiodarone, having the distinct and advantageous characteristic of being metabolized to a less lipophilic compound. This results in an improved safety profile. The new compounds have particular utility for treating life-threatening ventricular tachyarrhythmias, especially in patients with congestive heart failure (CHF). The compounds also provide effective management for ventricular arrhythmias and supraventricular arrhythmias, including atrial fibrillation and re-entrant tachyarrhythmias involving accessory pathways.

The present invention provides novel compounds of Formula Iand salts, hydrates, solvates, complexes, and prodrugs thereof. The present invention further provides methods for synthesizing compounds of Formula I. The invention additionally provides pharmaceutical compositions comprising the compounds of Formula I and methods of using the pharmaceutical compositions of Formula I to treat and prevent disorders and diseases associated with the RyR receptors that regulate calcium channel functioning in cells. Such disorders and diseases include, by way of example only, cardiac disorders and diseases, skeletal muscular disorders and diseases, cognitive disorders and diseases, malignant hyperthermia, diabetes, and sudden infant death syndrome. Cardiac disorder and diseases include, but are not limited to, irregular heartbeat disorders and diseases; exercise-induced irregular heartbeat disorders and diseases; sudden cardiac death; exercise-induced sudden cardiac death; congestive heart failure; chronic obstructive pulmonary disease; and high blood pressure. Irregular heartbeat disorders and diseases include and exercise-induced irregular heartbeat disorders and diseases include, but are not limited to, atrial and ventricular arrhythmia; atrial and ventricular fibrillation; atrial and ventricular tachyarrhythmia; atrial and ventricular tachycardia; catecholaminergic polymorphic ventricular tachycardia (CPVT); and exercise-induced variants thereof. Skeletal muscular disorder and diseases include, but are not limited to, skeletal muscle fatigue, exercise-induced skeletal muscle fatigue, muscular dystrophy, bladder disorders, and incontinence. Cognitive disorders and diseases include, but are not limited to, Alzheimer's Disease, forms of memory loss, and age-dependent memory loss.

Clinical studies of heart patients have demonstrated that ventricular tachyarrhythmia often is preceded by a foreshortened cardiac cycle length followed by a relatively long compensatory pause, thus producing in an abrupt short-to-long cycle length change. An implantable apparatus for preventing tachyarrhythmia measures the cardiac cycle length and detects the occurrence of a foreshortened cardiac cycle length more than a predefined amount between consecutive cycles. When a normal heart beat does not occur within a predefined period of time after such an abrupt change in cycle length, the resulting compensatory pause is eliminated by a cardiac pacer applying an appropriately timed electrical pulse to produce a contraction of the heart. The apparatus also includes a defibrillator to shock the heart in the event that the preventive pacing is not effective.

Provided herein are methods that include (i) determining a level of soluble ST2 in a biological sample from a subject, (i) comparing the level of soluble ST2 in the biological sample to a reference level of soluble ST2 (e.g., a level of soluble ST2 in the subject at an earlier time point), and (iii) selecting, implanting, replacing, or reprogramming an implanted cardiac device, e.g., an ICD, CRT, or CRT-D device, for a subject having an elevated level of soluble ST2 in the biological sample compared to the reference level of soluble ST2, or selecting a subject for participation in, or stratifying a subject participating in, a clinical study of a treatment for reducing the risk of a ventricular tachyarrhythmia (VTA) event. Also provided are methods for evaluating the risk of a VTA event in a subject. Also provided are kits for performing any of these methods.

An apparatus and method for terminating atrial and ventricular tachyarrhythmias by delivering a voltage pulse to an electrode arrangement that efficiently terminates the tachyarrhythmia. In one embodiment, a voltage pulse is impressed between an electrode located in the coronary sinus and an electrode located lo within the superior vena cava or right atrium which is also coupled to an extravascular electrode. In another embodiment, a voltage pulse is impressed between an electrode located within the right ventricle and electrodes located within the coronary sinus and the superior vena cava that are also coupled to an extravascular electrode.

Noncaptured atrial paces can result in long-short cardiac cycles which are proarrhythmic for ventricular tachyarrhythmia. Approaches are described which are directed to avoiding proarrhythmic long-short cycles. For cardiac cycles in which the atrial pace captures the atrium, a first post ventricular refractory period (PVARP) and a first A-A interval are used. For cardiac cycles in which the atrial pace does not capture the atrium, both an extended PVARP and an extended A-A interval are used. The A-A interval following a noncaptured atrial pace is extended from an atrial depolarization sensed during the extended PVARP.