46 results about "Ventricular Tachyarrhythmias" patented technology

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.

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.

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.

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.

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 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.

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.

Described herein are compositions and methods related to use of exosomes, including cardiosphere derived cell (CDC)-derived exosomes for treatment and prevention of heart related disease and conditions, such as ventral arrhythmias, such as tachycardias. CDC-derived exosomes delivered by endocardial injection can diminish the total amount of isolated late potentials associated with an isthmus of slow conduction, while reducing the isoelectric interval between late abnormal ventricular activity and decreasing the incidence of inducible ventricular arrhythmias, thereby providing a biological treatment for arrhythmias which otherwise requires therapeutic interventions with adverse effects.

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.