Abstract: A method discriminates between ventricular arrhythmia and supraventricular arrhythmia by determining the direction of an electrical signal conducted through the atrioventricular node. An implantable cardiac defibrillator provides atrioventricular and ventriculoatrial pacing bursts to determine if an arrhythmia with a 1:1 atrial to ventricular relationship is due to ventricular tachycardia or supraventricular tachycardia. This discrimination capability reduces the incidence of inappropriate shocks from dual-chamber implantable cardiac defibrillators to near zero and provides a method to differentially diagnose supraventricular tachycardia from ventricular tachycardia.

Abstract: An apparatus comprises plurality of sensors and a processor. Each sensor provides a sensor signal that includes physiological information and at least one sensor is implantable. The processor includes a physiological change event detection module that detects a physiological change event from a sensor signal and produces an indication of occurrence of one or more detected physiological change events, and a heart failure (HF) detection module. The HF detection module determines, using a first rule, whether the detected physiological change event is indicative of a change in HF status of a subject, determines whether to override the first rule HF determination using a second rules, and declares whether the change in HF status occurred according to the first and second rules.

Abstract: An implantable medical device (100) is configured for generating a cardiogenic impedance signal representative of the cardiogenic impedance of at least a portion of a heart (10) of a subject (20) during at least a portion of cardiac cycle. A moment processor (132) calculates a moment parameter value based on the cardiogenic impedance signal. The moment parameter is representative of a weighted sum of impedance amplitudes within a time window centered at defined time instance within the cardiac cycle. The weights of the impedance amplitudes are further dependent on the length in time between the defined time instance and the point of time of the associated impedance amplitude. The moment parameter is of high diagnostic value and is employed by an arrhythmia classifier (132) in order to classify a detected arrhythmia of the heart (10), such as discriminate between hemodynamically stable or unstable arrhythmias and/or supraventricular or ventricular tachycardia.

Abstract: An apparatus and method for remotely managing a disease. The apparatus includes a sensor having a first determining unit for determining whether a measured biosignal has a normal waveform, and a transmitter for transmitting the biosignal to a server when the biosignal is determined to have an abnormal waveform.

Abstract: Embodiments of the invention provide methods for the detection and treatment of atrial fibrillation (AF) and related conditions. One embodiment provides a method comprising measuring electrical activity of the heart using electrodes arranged on the heart surface to define an area for detecting aberrant electrical activity (AEA) and then using the measured electrical activity (MEA) to detect foci of AEA causing AF. A pacing signal may then be sent to the foci to prevent AF onset. Atrial wall motion characteristics (WMC) may be sensed using an accelerometer placed on the heart and used with MEA to detect AF. The WMC may be used to monitor effectiveness of the pacing signal in preventing AF and/or returning the heart to normal sinus rhythm (NSR). Also, upon AF detection, a cardioversion signal may be sent to the atria using the electrodes to depolorize an atrial area causing AF and return the heart to NSR.

Abstract: Apparatus and methods are provided including sensing at least one parameter of a subject while the subject sleeps. The parameter is analyzed, and a condition of the subject is determined at least in part responsively to the analysis. The subject is alerted to the condition only after the subject awakes. Other applications are also described.

Abstract: Systems and methods of detecting an impending cardiac decompensation of a patient measure an electrocardiogram signal of the patient. An incidence of cardiac arrhythmias is determined from the electrocardiogram signal. A risk of impending decompensation is determined in response to the incidence of cardiac arrhythmias. In many embodiments, the impending decompensation can be detected early enough to avoid, or at least delay, the impending decompensation, such that patient trauma and/or expensive ICU care can be avoided. Although embodiments make specific reference to monitoring electrocardiogram and other physiological signals with an adherent patch, the system methods and devices are applicable to many applications in which physiological monitoring is used, for example wireless physiological monitoring with implanted sensors for extended periods.

Abstract: A method and system for determining the mechanism of cardiac arrhythmia in a patient is disclosed. The method basically entails measuring the impedance of cardiac tissue in a portion of the patient's heart using a catheter during an episode of supraventricular tachycardia to produce an iso-impedance map of that cardiac tissue on a video display and analyzing the pattern of the iso-impedance map to differentiate focal arrhythmia caused by a circumscribed region of focal firing and reentrant arrhythmia caused by a macroreentrant circuit. The method can also be used to identify regions of coherent rapidly conducting tissue e.g., Bachman's bundle or the inferoposterior pathway insertion points, to identify focal “mother rotors” throughout the left atrium that may participate in the generation and maintenance of atrial fibrillation and to identify areas of CAFE (complex atrial/fractionated electrograms) that truly reflect these mother rotors.

Abstract: The present invention provides an improved, Internet-based system that seamlessly collects cardiovascular data from a patient before, during, and after a procedure for EP or an ID. During an EP procedure, the system collects information describing the patient's response to PES and the ablation process, ECG waveforms and their various features, HR and other vital signs, HR variability, cardiac arrhythmias, patient demographics, and patient outcomes. Once these data are collected, the system stores them on an Internet-accessible computer system that can deploy a collection of user-selected and custom-developed algorithms. Before and after the procedure, the system also integrates with body-worn and/or programmers that interrogate implanted devices to collect similar data while the patient is either ambulatory, or in a clinic associated with the hospital. A data-collection/storage module, featuring database interface, stores physiological and procedural information measured from the patient.

Abstract: Techniques identify origins of ventricular arrhythmias (e.g., ventricular tachycardia or premature ventricular complexes) including exit sites or other sites using a single or multi-lead electrocardiogram (ECG) assembly. The ECG assembly is used to map an organ into a series of different three-dimensional (3D) regions. Pace maps or ventricular arrhythmia signals are used in form of ECG signals along with a supervised learning methods to pinpoint the potential origin of VT, i.e., exit sites, in the various regions.

Abstract: System, assembly and method are provided to facilitate reconstruction of cardiac information representing a complex rhythm disorder associated with a patient's heart to indicate a source of the heart rhythm disorder. The complex rhythm disorder can be treated by application of energy to modify the source of the rhythm disorder.

Abstract: Approaches for determining threshold values for one or more arrhythmia rate zones and/or the number of rate zones are described. A probability function for heart rate is determined using collected and measured heart rate values. One or more heart rate probability values are selected. Thresholds for arrhythmia rate zones are determined from the probability function based on the selected probability values. Determining the rate zone thresholds may involve determining a threshold for a lower rate limit and/or determining one or more tachyarrhythmia rate zone thresholds. The number of rate zones may also be determined based on the probability function.

Abstract: A late potential detecting system has an implantable medical device connected to at least one cardiac lead having implantable electrodes positioned at different sites of a ventricle myocardium. A sampling unit of the implantable medical device records electrogram samples for the different implantable electrodes to get different sample sets. The electrogram samples of the sample sets are time synchronized and magnitude potential representations of the potential data of the electrogram samples are determined. The magnitude potential representations of the time synchronized electrogram samples are then co-processed and used for determining a parameter that is indicative of any late potentials of the monitored ventricle.

Abstract: Methods of cardiac rhythm analysis in an implantable cardiac stimulus device, and devices configured for such methods. In an illustrative embodiment, certain data relating to cardiac event rate or amplitude is modified following delivery of a cardiac stimulus. In another embodiment, cardiac rhythm analysis is performed using one of plural states, with the plural states using different criteria, such as a detection threshold, to detect cardiac events in a sensed signal. Following delivery of a cardiac stimulus, data is manipulated to force the analysis into one of the states, where stimulus is delivered, in the illustrative embodiment, only after a different state is invoked. Implantable devices incorporating operational circuitry for performing such methods are also included in other illustrative embodiments.

Abstract: An implantable medical device is provided for detecting transportless ventricular rhythm of a heart lacking atrial transport and comprises a housing, sensors configured to be located proximate to a heart, a sensing module to sense cardiac signals representative of a rhythm originating from the heart and a rhythm detection module. The rhythm detection module determines a change in AV association and identifies a potential ventricular complex with loss of atrial transport (VCLAT) based on the change in AV association.

Abstract: Systems and techniques for managing biological signals. In one implementation, a method includes receiving a cardiac biological signal that includes information describing events, determining a merit of each event based on one or more of a severity of a cardiac condition associated with the event and a quality of the event, and handling a subset of the events that meet a merit criterion. The subset can be handled for medical purposes.

Abstract: A cardiac-based metric is computed based upon characteristics of a subject's cardiac function. In accordance with one or more embodiments, the end of a mechanical systole is identified for each of a plurality of cardiac cycles of a subject, based upon an acoustical vibration associated with closure of an aortic valve during the cardiac cycle. The end of an electrical systole of an electrocardiogram (ECG) signal for each cardiac cycle is also identified. A cardiac-based metric is computed, based upon a time difference between the end of the electrical systole and the end of the mechanical systole, for the respective cardiac cycles.

Abstract: A method, system, stethoscope and server for classifying a cardiovascular sound recorded from a living subject. The method comprises the steps of: identifying diastolic and/or systolic segments of the cardiovascular sound; dividing at least one of the identified diastolic and/or systolic segments into a number of sub-segments comprising at least a first sub-segment and at least a second sub-segment; extracting from the first sub-segment at least a first signal parameter characterizing a first property of the cardiovascular sound, extracting from the second sub-segment at least a second signal parameter characterizing a second property of the cardiovascular sound; and classifying the cardiovascular sound using the at least first signal parameter and the at least second signal parameter in a multivariate classification method.

Abstract: A non-transitory computer-readable medium can have instructions executable by a processor. The instructions can include an electrogram reconstruction method to generate reconstructed electrogram signals for each of a multitude of points residing on or near a predetermined cardiac envelope based on geometry data and non-invasively measured body surface electrical signals. The instructions can include a phase calculator to compute phase signals for the multitude of points based on the reconstructed electrogram signals and a visualization engine to generate an output based on the computed phase signals.

Abstract: A method and system for predicting the onset of heart arrhythmias more accurately observes trends in abnormal or pathologic morphology of the electrocardiogram (ECG). A first set of ECG signals is monitored from a patient. A baseline measurement is generated from the monitored first set of ECG signals to contain nonpathologic ECG morphologies in each lead. A second set of ECG signals is monitored from the patient and the baseline measurement is subtracted from the second set of ECG signals on a beat-to-beat basis. Afterwards, a residuum signal is generated for each lead based on the subtraction. R-wave heterogeneity, T-wave heterogeneity, P-wave heterogeneity, or ST-segment heterogeneity or other indicators of arrhythmia risk or myocardial ischemia are quantified based on the generated residuum signals.

Abstract: A medical monitoring device for monitoring electrical signals from the body of a subject is described. The medical monitoring device monitors electrical signals originating from a cardiac cycle of the subject and associates each cardiac cycle with a time index. The medical monitoring device applies a forward computational procedure to generate a risk score indicative of hyperkalemia, hypokalemia or arrhythmia of the subject. The medical monitoring device can adjust the forward computational procedure based upon clinical data obtained from the subject.

Abstract: Apparatus and methods are provided for monitoring a subject, including setting respective first and second thresholds that are different from one another, sensing at least one parameter of the subject, and analyzing the parameter to generate a score. If the score is between the first and second thresholds, an alert that is indicative of a condition of the subject is generated only after the subject awakes. If the score passes the second threshold, an alert that is indicative of the subject's condition is generated immediately. Other applications are also described.

Abstract: This invention relates to fitness monitors and the like. This invention is more particularly directed to a device and a method for facilitating quantitative evaluation of level of physical fitness (fitness score) including a PC or handheld, or watch type electronic device having input and output means based on formulas for calculating level of physical fitness through heart rate variability analysis during orthostatic intervention by assessing two main parameters, such as level of adaptation reserve and wellness level.

Abstract: A method of detecting cardiac signals in a medical device that includes decomposing a cardiac signal using a wavelet function at a plurality of scales to form a corresponding wavelet transform, determining approximation coefficients in response to the plurality of scales, reconstructing a first wavelet representation of the wavelet transform using predetermined approximation coefficients of the determined approximation coefficients, and evaluating the detected cardiac signals in response to the reconstructing.

Abstract: A device for detecting cardiac ischemia is disclosed. The device includes a processor that is configured to distinguish between two different heart beats types such as left bundle branch block beats and normal sinus beats. The processor applies different ischemia tests to the two different beat types, and generates alert when it detects ischemia.

Abstract: Embodiments of the present invention relate to implantable systems, and methods for use therein, that can detect T-wave alternans and analyze the detected alternans to provide information regarding cardiac instabilities and predict impending arrhythmias.

Abstract: An example system and method of processing cardiac activation information are disclosed. The method includes accessing a first cardiac signal and a second cardiac signal obtained from a patient. The first cardiac signal and the second cardiac signal are processed to identify a point of change in the first cardiac signal at which a derivative of the first cardiac signal diverges with respect to a derivative of the second cardiac signal. An activation onset time is assigned in the first cardiac signal at the point of change to define a cardiac activation.

Abstract: The invention relates to a method, system, and software product for measuring heart rate variability. The method comprises displaying an animation that indicates to the user when to breathe in and breathe out, receiving a signal from a sensor responsive to the heart beat of the user, processing the received signal to determine heart beat intervals of the user and calculating a measure of heart rate variability of the user from the processed heart beat intervals.

Abstract: The present invention, in illustrative embodiments, includes devices for analyzing cardiac signals in an implantable cardiac stimulus system. Within the analysis, a threshold may be defined related to a cardiac event rate. If the cardiac event rate does not exceed the threshold, filtering of captured cardiac signals occurs, including attenuating T-waves. If the cardiac event rate does exceed the threshold, circuitry for analog filtering or programming for digital filtering is bypassed to avoid attenuating low frequency components of the captured cardiac signals.

Abstract: An ECG signal processing system which removes the CPR-induced artifact from measured ECG signals obtained during the administration of CPR.

Abstract: Techniques are provided for updating a morphology template used to discriminate abnormal cardiac rhythms. In one example, a non-weighted candidate morphology template is generated based on far-field R-wave morphology. A weighted candidate morphology template is generated based on an ensemble average of the non-weighted candidate morphology template and a previous (i.e. active) morphology template. The previous morphology template is then selectively updated based on a comparison of additional R-waves against both the non-weighted and the weighted candidate templates. Thereafter, abnormal cardiac rhythms such as ventricular tachycardia and supraventricular tachycardia are discriminated using the updated morphology template based on newly-detected far-field R-waves. These techniques provide a method for updating the morphology discrimination template in response to long-term changes in morphology due to cardiac remodeling or cardiac disease progression.

Abstract: A method for analysis of cardiac rhythms and the clinical status of a patient, based on calculations of entropy and moments of time series intervals. An optimal determination is made of segments of data that demonstrate statistical homogeneity, specifically with regard to moments and entropy. The invention also involves calculating moments and entropy on each interval segments with the goal of diagnosis of cardiac rhythm. More specifically, an absolute entropy measurement is calculated, providing dynamic information of fundamental importance in diagnosis and analysis.

Abstract: An embodiment of the invention provides an apparatus for the detection and treatment of atrial arrhythmia comprising an electrical lead having proximal and distal portions. The distal portion is positionable in an atrial chamber and the end of the proximal portion is configured to be coupled to a pacemaker. The lead comprises a plurality of conductive wires clad with an insulative coating and has sufficient flexibility to be positioned in the atria from a percutaneous introductory site. The conductive wires are coupled to a plurality of pairs of bipolar electrodes positioned on a membrane attachable to an endocardial wall. The electrode pairs are distributed in a pattern defining an area for detecting a location of a foci of aberrant electrical activity located within or adjacent the area and sending a pacing signal to that location to prevent or stop an occurrence of atrial fibrillation caused by that foci.

Abstract: A method and system for determining the mechanism of cardiac arrhythmia in a patient is disclosed. The method basically entails measuring the impedance of cardiac tissue in a portion of the patient's heart using a catheter during an episode of supraventricular tachycardia to produce an iso-impedance map of that cardiac tissue on a video display and analyzing the pattern of the iso-impedance map to differentiate focal arrhythmia caused by a circumscribed region of focal firing and reentrant arrhythmia caused by a macroreentrant circuit. The method can also be used to identify regions of coherent rapidly conducting tissue e.g., Bachman's bundle or the inferoposterior pathway insertion points, to identify focal “mother rotors” throughout the left atrium that may participate in the generation and maintenance of atrial fibrillation and to identify areas of CAFE (complex atrial/fractionated electrograms) that truly reflect these mother rotors.

Abstract: An implantable medical device such as an implantable pacemaker or implantable cardioverter/defibrillator includes a programmable sensing circuit providing for sensing of a signal approximating a surface electrocardiogram (ECG) through implanted electrodes. With various electrode configurations, signals approximating various standard surface ECG signals are acquired without the need for attaching electrodes with cables onto the skin. The various electrode configurations include, but are not limited to, various combinations of intracardiac pacing electrodes, portions of the implantable medical device contacting tissue, and electrodes incorporated onto the surface of the implantable medical device.

Abstract: A medical device performs a method for determining a cardiac event by obtaining a signal comprising cardiac cycle length information in a patient and determining cardiac cycle lengths during an established time interval. Noise is detected during the time interval and a cardiac cycle length corresponding to a time of the detected noise is rejected. Cycle length differences are determined from the cycle lengths not rejected during the time interval. The cardiac event is determined in response to the cycle length differences.

Abstract: An implantable medical device (IMD), such as an implantable pacemaker, cardioverter, or diagnostic device, generates an EGM signal, e.g., a far field EGM signal, samples the EGM signal to obtain a single T-wave amplitude value for each T-wave over a plurality of beats, and stores the T-wave amplitude values in memory. The IMD creates a time series of the T-wave amplitude values stored in memory, calculates the power spectral density for the times series, and selects a power spectral density of a particular frequency, e.g., 0.5 cycles per beat, as the TWA value. The IMD may periodically determine TWA values for the patient and store the values in memory. The TWA values may be presented to medical personnel, e.g., as a trend. The IMD may deliver or modify therapy, or provide an alert, based on the TWA values.

Abstract: A medical device and associated method establish an occurrence of a premature atrial contraction. The device senses a ventricular signal. A control unit is configured to determine a metric of the ventricular signal during an interval following the premature atrial contraction and detect a change in cardiac stress tolerance in response to the determined metric.

Abstract: Embodiments of the present invention relate to implantable systems, and methods for use therewith, for monitoring myocardial electrical stability. A patient's heart is paced for a period of time using a patterned pacing sequence that repeats every N beats, and an electrical signal is obtained that is representative of a plurality of consecutive beats of the patient's heart while it is being paced using the patterned pacing sequence that repeats every N beats. Myocardial electrical stability is then analyzed using frequency domain techniques that are tailored to the patterned pacing sequence used to pace the patient's heart. In other embodiments, the patient's heart need not be paced. This abstract is not intended to be a complete description of, or limit the scope of, the invention.

Abstract: The present invention relates to methods for predicting the risk for ventricular arrhythmias in a subject who has previously suffered a myocardial infarction (MI) or suffers from a primary cardiomyopathy, said method comprising measuring the myocardial mechanical dispersion in said subject and estimating the risk for ventricular arrhythmias based on said measurements. Similar the invention relates to a method for evaluating whether a subject is a candidate for implantable cardioverter-defibrillator (ICD) therapy.

Abstract: A medical device is provided that comprises a lead assembly. The lead assembly includes at least one intra-cardiac (IC) electrode, an extra-cardiac (EC) electrode and a subcutaneous remote-cardiac (RC) electrode. The IC electrode is configured to be located within the heart. The EC electrode is configured to be positioned proximate to at least one of a superior vena cava (SVC) and a left ventricle (LV) of a heart. The RC electrode is configured to be located remote from the heart. An extra-cardiac impedance (ECI) module is configured to measure extra-cardiac impedance along an ECI vector between the EC and RC electrodes to obtain ECI measurements. An arrhythmia monitoring module is configured to declare a potential atrial arrhythmia to be an atrial arrhythmia based on the hemodynamic performance determined from the ECI measurements. The hemodynamic performance assessment module is further enabled to compare a current ECI pattern with a prior baseline ECI waveform.

Abstract: Disclosed herein methods, devices, and systems for detecting and diagnosing a heart disease or disorder in a subject from a prime electrocardiogram which comprises calculating at least one distribution function of the prime electrocardiogram and determining whether the distribution function is indicative of the presence of absence of the heart disease or disorder.

Abstract: A method for monitoring a heart of a patient, the includes receiving signals indicative of cardiac activity of the patient during a monitoring period; and processing the signals and providing monitoring results in response to a result of the processing; wherein the monitoring results comprise information indicative of: (a) the heart rate of the patient during the monitoring period; (b) at least one first time period in which the heart rate of the patient exceeds a first threshold; and (c) at least one second time period in which the heart rate of the patient exceeds both the first threshold and a second threshold

Abstract: A method is disclosed for displaying patient ECG data. The method includes receiving ECG data including an ECG waveform; receiving analyzed ECG data including arrhythmic events; generating an indicia of the detected arrhythmic event; and displaying the indicia of the detected arrhythmic event in relation to the ECG waveform at a position associated with a time of the detected arrhythmic event. A system for displaying patient ECG data is also disclosed.

Abstract: An implantable medical device and associated method for classifying a patient's risk for arrhythmias by sensing a cardiac electrogram (EGM) signal and selecting a first pair of T-wave signals and a second pair of T-wave signals. A first difference between the two T-wave signals of the first pair is compared to a second difference between the two T-wave signals of the second pair. A T-wave alternans phase reversal is detected in response to comparing the first difference and the second difference, and the patient's arrhythmia risk is classified in response to detecting the phase reversal.

Abstract: A method of detecting a cause of a heart rhythm disorder includes collecting data corresponding to activation onset time of each heart activation at multiple locations of the heart and generating an activation trail based on the sequential order of activation onset times. The activation trail is indicative of the cause of the heart rhythm disorder.

Abstract: Embodiments of the present invention relate to implantable systems, and methods for use therewith, for monitoring myocardial mechanical stability based on a signal that is indicative of mechanical functioning of a patient's heart for a plurality of consecutive beats. Certain embodiments use time domain techniques, while other embodiments use frequency domain techniques, to monitor myocardial mechanical stability. In certain embodiments the patient's heart is paced using a patterned pacing sequence that repeats every N beats. In other embodiments, the patient's heart need not be paced. This abstract is not intended to be a complete description of, or limit the scope of, the invention.

Abstract: Physiologic demand driven pacing can be used to maintain cardiac synchrony and improve hemodynamic function in patients with heart failure.

Abstract: The present invention comprises a cardiopulmonary resuscitation (CPR) feedback device and a method for performing CPR. A chest compression detector device is provided that measures chest compression during the administration of CPR. The chest compression detector device comprises a signal transmitter operably positioned on the chest of the patient and adapted to broadcast a signal, and a signal receiver adapted to receive the signal. The chest compression detector device also comprises a processor, operably connected to the signal transmitter and the signal receiver. The processor repeatedly analyzes the signal received to determine from the signal a series of measurements of compression of the chest, and feedback is provided to the rescuer based on the series of measurements.

Abstract: While analyzing ventricular repolarization in accordance with the invention, ECG measurement with excitation of heart rate is evaluated and the coupling of an internal parameter, for example QT to heartbeat interval, for example RR, is modeled by a transfer function with three parameters. The values of the resulting five parameters describing the static and dynamic characteristics of ventricular repolarization are obtained by means of transfer function parameters and the measured values of heart rate and the internal parameter. The effect of medication is evaluated from the difference of the values of these parameters determined before and after administrating the medication.