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.

Abstract: An implantable medical device (IMD) identifies suspected non-lethal ventricular arrhythmia, and takes one or more actions in response to the identification to avoid or delay delivery of a defibrillation or cardioversion shock. The IMD employs number of intervals to detect (NID) thresholds for detection of ventricular arrhythmias. When a NID threshold is met, the IMD determines whether the ventricular rhythm is a suspected non-lethal rhythm despite satisfying a NID threshold. In some embodiments, the IMD increases the NID threshold, i.e., extends the time for detection, in response to identifying a rhythm as a suspected non-lethal rhythm, and monitors subsequent ventricular beats to determine if the increased NID threshold is met before detecting a ventricular arrhythmia and delivering therapy. The IMD can determine whether a rhythm is a suspected non-lethal arrhythmia by, for example, comparing the median ventricular cycle length (VCL) to the median atrial cycle length (ACL).

Abstract: A method includes retrieving electrogram (EGM) data for N cardiac cycles from a memory of an implantable medical device. N is an integer greater than 1. The method further include categorizing each of the N cardiac cycles into one of a plurality of categories based on a morphology of the N cardiac cycles and performing comparisons between pairs of the N cardiac cycles. Each of the comparisons between two cardiac cycles includes detecting a mismatch between the two cardiac cycles when the two cardiac cycles are in different categories, and detecting a match between the two cardiac cycles when the two cardiac cycles are in the same category. Additionally, the method includes classifying the rhythm of the N cardiac cycles based on a number of detected matches and detected mismatches.

Abstract: A method for analysis of cardiac rhythm and RR interval time series based on entropy related data and entropy based measures. The information is related to but distinct from entropy, and is derived from histograms of interval match counts in which the y-axis is the frequency of intervals of length in that have the match count given on the x-axis. The phenotype of the histogram informs on the presence of atrial fibrillation or, in the presence of sinus rhythm, the degree of congestive heart failure.

Abstract: Techniques include determining a first vector of temporal changes in electrical data measured at multiple electrical sensors positioned at corresponding locations on a surface of a living body due to a natural electrical pulse. A different vector of temporal changes in electrical data measured at the same electrical sensors is determined due to each stimulated signal of multiple stimulated signals within the living body. Stimulated position data is received, which indicates a different corresponding position within the living body where each of the stimulated signals originates. The site of origin of the natural electrical pulse is determined based on the first vector and the multiple different vectors and the stimulated position data. Among other applications, these techniques allow the rapid, automatic determination of the site of origin of ventricular tachycardia arrhythmia (VT).

Abstract: A method of detecting atrial fibrillation (AFib) includes receiving electrical signals representative of a beating heart and measuring atrial activity over a time window of three or more beats. The method may also include measuring beat interval variation over the time window and combining the measures of atrial activity and beat interval variation to produce an indication of an atrial fibrillation condition in the electrical signal. The method may further include producing the indication with a processing system. Measuring atrial activity may include measuring P waves, and measuring P waves may include analyzing a standard deviation of a PR interval.

Abstract: Methods for determination of timing for electrical shocks to the heart to determine shock strength necessary to defibrillate a fibrillating heart. The timing corresponds the window of most vulnerability in the heart, which occurs during the T-wave of a heartbeat. Using a derivatized T-wave representation, the timing of most vulnerability is determined by a center of the area method, peak amplitude method, width method, or other similar methods. Devices are similarly disclosed embodying the methods of the present disclosure.

Abstract: An arrhythmia classification system receives cardiac data from an implantable medical device, performs automatic adjudication of each cardiac arrhythmia episode indicated by the cardiac data, and generates episode data representative of information associated with the episode. The episode data include at least an episode classification resulting from the automatic adjudication of the episode and a confidence level in the episode classification. In one embodiment, the episode data further include key features rationalizing the automatic adjudication of the episode.

Abstract: An atrial fibrillation (AF) monitor extracts two P wave features and an R-R interval feature from a sequence of ECG waveforms. The features are used by a classifier to classify a heart rhythm as AF or non-AF. The AF classification results may be further processed to reduce false alarm reporting. The AF classification results are used by an AF burden calculator to report AF burden in real time.

Abstract: The invention concerns the therapy with a cardiac resynchronization device (CRT) and/or therapy with an automated internal cardiac defibrillator (ICD) for treating patients with any cancer or patients with cachexia due to acute or chronic illness other than cardiac illness, including malignant tumor disease, COPD, chronic renal failure, liver cirrhosis, chronic infections, and/or AIDS. Areas of application are the life sciences, in particular medicine and medical technology.

Abstract: A device and method of detecting the severity of myocardial ischemia and heart attack risk is provided. The method includes obtaining an electrogram signal, determining T-wave measurements based on the electrogram signal, and determining ST segment measurements based on the electrogram signal. The method also includes identifying T-wave alternans based on the T-wave measurements and identifying ST segment changes based on the ST segment measurements. The method further includes correlating the T-wave alternans with the ST segment changes in order to detect a severity of ischemia.

Abstract: A method, apparatus, and computer program product for predicting ventricular tachyarrhythmia (VTA) are disclosed. To provide a mechanism that allows prediction of VTA events efficiently within a few hours before the onset of the actual event, a set of repolarization parameters indicative of ventricular repolarization in a subject's heart is determined in successive time segments, thereby to obtain a time series of the set of repolarization parameters. Based on the time series, at least one change indication variable indicative of changes in the ventricular repolarization of the heart is produced and the risk of potential ventricular tachyarrhythmia is predicted based on the at least one change indication variable.

Abstract: Provided herein are implantable systems, and methods for use therewith, for characterizing a tachycardia and/or selecting treatment for a tachycardia using results of a fractionation analysis. One or more electrogram (EGM) signal(s) indicative of cardiac electrical activity are obtained. At least one of the EGM signal(s) is analyzed to determine whether the EGM signal is fractionated, and the results of the analyzing are used to characterize a tachycardia and/or to select treatment for a tachycardia.

Abstract: A medical device and associated method for discriminating cardiac events includes determining whether a first match score is within a first match zone having a first correlation with a non-treatable cardiac event, a second match zone having a second correlation with the non-treatable cardiac event less than the first correlation with the non-treatable event, a third match zone having a first correlation with a treatable cardiac event, and a fourth match zone having a second correlation with the treatable cardiac event greater than the first correlation with the treatable cardiac event. A determination is made as to whether a second match score and a third match score are within the first match zone, the second match zone, the third match zone and the fourth match zone to generate a first adjusting factor, and cardiac event evidence is accumulated in response to the first adjusting factor for discriminating cardiac events.

Abstract: A cardiac muscle excitation waveform detector including: a waveform acquisition section that acquires, in a preset period, a waveform from an intracardiac electrocardiogram measured in middle of occurrence of atrial fibrillation; a waveform detection condition setting section that sets conditions for detecting a waveform of cardiac muscle excitation; and an excitation waveform detection section that detects a waveform of cardiac muscle excitation from the waveforms based on the conditions, wherein the waveform detection condition setting section includes a section that sets conditions based on a contour of a waveform to detect candidates for the waveform of cardiac muscle excitation, a section that sets a search period for searching for a waveform of cardiac muscle excitation; and a section that sets a preset period subsequent to detection as a detection exclusion period during which the candidate waveforms are not detected when the waveform of cardiac muscle excitation is detected.

Abstract: The present invention relates to a method for assessing the electrical function of a heart, comprising the steps of:—(1) for each of a plurality of leads of an ECG, determining a value derived from the output of that lead and which corresponds to an action potential duration; (2) for each of the plurality of leads of the ECG, determining a value derived from the output of that lead and which corresponds to a diastolic interval; (3) for each of the plurality of leads of the ECG, determining a relationship between the determined values for action potential duration and for diastolic interval; (3) assessing the differences between the determined relationships for each of the plurality of leads. The invention further relates to apparatus and a computer program that may be used in the method.

Abstract: An RI measurement/notification apparatus includes: a displaying section configured to display waveform data of an intracardiac electrocardiogram; a waveform data acquiring section configured to acquire waveform data in a preset waveform data acquisition time period from an intracardiac electrocardiogram during atrial fibrillation; an RI calculating section configured to calculate an RI value based on the waveform data acquired by the waveform data acquiring section; and a notifying section configured to, in a case where the RI value calculated by the RI calculating section exceeds a preset threshold, notify that the value exceeds the threshold.

Abstract: A device senses cardioelectrical signals using a right atrial (RA) lead, which might include far-field R-waves as well as near-field P-waves. The device concurrently senses events using a proximal electrode of an LV lead, which can sense both P-waves and R-waves as substantially near-field events. Suitable templates are then applied to the signals sensed via the proximal LV electrode to identify the origin of the signals (e.g. atrial vs. ventricular) so as to properly classify the corresponding events sensed in the RA as near-field or far-field events. In this manner, far-field oversensing is conveniently detected.

Abstract: Cardiac arrhythmias are classified based on the morphology of the arrhythmia episode beats. Templates are formed using morphological features of the cardiac beats of the episode. The arrhythmia episode is classified as a monomorphic tachyarrhythmia or polymorphic tachyarrhythmia based on the one or more templates. The arrhythmia episode may be classified based on a number templates formed from the arrhythmia episode. The templates are formed by determining a measure of similarity between morphological features of a cardiac beat to a template. The similarities can be determined based on a pairing rule that determines which beat morphologies are compared. Selection of therapy for treating the arrhythmia episode may depend on the historical success of a therapy at mitigating previous arrhythmias of the same type as the arrhythmia episode.

Abstract: A system including a communication module, a processor and a medical device configured to sense cardiac signals and detect cardiac rhythm episodes is configured to retrieve stored episode data accumulated by the medical device and generate truthed episode classifications from the retrieved episode data. The processor is configured to perform a detection simulation for detecting and classifying cardiac rhythm episodes included in the retrieved episode data to obtain simulated episode classifications. Sensitivity and specificity data is generated in response to the detection simulation, and recommended detection parameter settings are identified in response to the sensitivity and specificity data.

Abstract: A method includes storing an electrogram (EGM) template in a memory. The EGM template includes first and second alignment points at first and second peaks of the EGM template, respectively. The method further includes identifying first and second peaks of a cardiac cycle EGM acquired by a medical device and selecting one of the first and second peaks of the cardiac cycle EGM to align with one of the first and second alignment points based on an order in which the first and second peaks of the cardiac cycle EGM occur. Additionally, the method includes aligning the selected one of the first and second peaks with one of the first and second alignment points and determining an amount of similarity between the cardiac cycle EGM and the EGM template after alignment.

Abstract: Embodiments of the present invention relate to monitoring a patient's atrial stretch, heart failure (HF) condition, and/or risk of atrial fibrillation (AF), as well as methods for estimating a change in at least one of a patient's left atrial pressure (LAP), pulmonary capillary wedge pressure (PCWP), and right pulmonary artery pressure (RPAP). Embodiments of the present invention also relate to selecting a pacing energy level. Such embodiments involve determining atrial evoked response metrics when a patient's atrium is paced, and monitoring changes in such metrics.

Abstract: Disclosed is an apparatus and method for ambulatory, real-time detection of removal of ectopic beats by obtaining consecutive patient heartbeats, and recognizing an ectopic beat by detecting a signature short-long sequence in an interbeat interval of the obtained heartbeats, with the signature short-long sequence including an ectopic coupling interval followed by a compensatory pause between RR intervals.

Abstract: A system comprises a physiologic sensing circuit configured to generate physiologic data for a subject and a processing circuit. The processing circuit includes a data parsing circuit configured to parse the physiologic data to identify one or more physiologic events and a report generation circuit. The report generation circuit is configured to associate narrative text with the identified physiologic events according to a text generating rule and generate a narrative report for the identified physiologic events using the narrative text.

Abstract: An apparatus and a method to generate an atrial fibrillation prediction model, and an apparatus and a method to predict atrial fibrillation are provided. An atrial fibrillation (AF) prediction model generating apparatus includes a feature extractor configured to extract T-wave features in a predetermined time period from electrocardiogram data and generate a T-wave feature profile based on the extracted features, and a prediction model generator configured to classify the generated T-wave feature profile and generate an AF prediction model using the classified feature profile.

Abstract: Techniques for detecting tachyarrhythmia and also for preventing T-wave oversensing use signals filtered by a narrowband bradycardia filter in combination with signals filtered by a narrowband tachycardia filter. A separate wideband filter may also be used.

Abstract: An atrial fibrillation classification system collects celectrocardiogram signals and converts them to a frequency, time, or phase domain representation for analysis. An evaluation stage extracts energy density profile over a range of frequencies, time intervals, or phases, which is then summed and normalized to form dispersion metrics. The system then analyzes the dispersion metrics, in their respective domains, to determine whether a patient is experiencing an arrhythmia and then to classify the type of arrhythmia being experienced.

Abstract: Systems and methods of processing raw electrocardiogram (ECG) waveform data of a patient into estimated real-time ECG waveform data. The method includes sensing at least one physical non-cardiac influence on the raw ECG waveform data, constructing a time domain computer model of the at least one physical, non-cardiac influence on the raw ECG waveform data, and adaptively filtering the raw ECG waveform data in the time domain using the constructed time domain computer model of the at least one physical non-cardiac influence on the raw ECG waveform data to form the estimated real-time ECG waveform data. The system can include an ECG device for collecting raw ECG waveform data, at least two ECG electrodes positioned on the patient and electrically coupled to the ECG device, and a processor coupled to the ECG device and configured to compute a time domain model of an artifact created by chest compressions.

Abstract: An electrocardiogram (ECG) analyzing system for analyzing electrocardiogram (ECG) signals, the system including: a computing device including: a transformer for transforming an ECG signal into a time-frequency representation over a plurality of frequencies over a period of time; a calculator for calculating a magnitude of the time-frequency representation; an analyzer for analyzing a degree of clustering of a plurality of low-magnitude values in the time-frequency representation; and a diagnosing system for diagnosing whether ventricular fibrillation is present based on the degree of clustering.

Abstract: A system and method for automatically analyzing a cardiac signal, including the step of providing an episode database on a computer storage medium including a plurality of episode data records of one or more patients. Each episode data record includes a cardiac signal from at least one data-generating device. The method also includes the step of selecting one or more of the N beats to be one or more beat templates, for at least a first cardiac signal having N beats. Another step is determining a value K for the cardiac signal using a computer system where K beat templates can represent all the N beats in the cardiac signal.

Abstract: An apparatus comprises an implantable cardiac signal sensing circuit configured to produce a sensed cardiac signal representative of cardiac activity of a subject and a controller communicatively coupled to the cardiac signal sensing circuit. The controller includes a sensing module configured to detect a cardiac depolarization using the sensed cardiac signal and an arrhythmia detection module. The arrhythmia detection module is configured to detect a depolarization rate or interval that satisfies a first tachyarrhythmia detection rate zone threshold, adjust a specified detection duration threshold for the tachyarrhythmia detection zone according to the detected depolarization rate, declare that the detected depolarization rate is an episode of tachyarrhythmia when the detected depolarization rate is sustained for the adjusted detection duration threshold, and provide an indication of the tachyarrhythmia to a user or process.

Abstract: Methods and systems for automatic detection of Atrial Fibrillation (AF) are disclosed. The methods and systems use time-varying coherence functions (TVCF) to detect AF. The TVCF is estimated by the multiplication of two time-varying transfer functions (TVTFs).

Abstract: Detected changes in atrial activation can be used to discriminate between hemodynamically stable and hemodynamically unstable tachyarrhythmias.

Abstract: Systems and techniques are disclosed for determining the onset and offset of a ventricular fibrillation event and for distinguishing ventricular fibrillation from noise. In some examples, an electrocardiogram (ECG) signal is obtained; a transform is applied to the ECG signal to obtain an analytical pair, the analytical pair including the ECG signal and the transformed ECG signal; a speed-amplitude is determined from the analytical pair; and an onset of a ventricular fibrillation event is identified based at least one of a value of a cost function of the speed-amplitude over a window and a quantity of occurrences the speed-amplitude crosses a threshold over the window.

Abstract: The present invention relates to the use of dronedarone or a pharmaceutically acceptable salt thereof for the preparation of a drug for the prevention of atrial fibrillation wherein said use comprises the following precaution of use steps: a) initiating dronedarone administration in patients with atrial fibrillation or atrial flutter, b) performing electrocardiograms serially.

Abstract: Methods, systems, and devices for signal analysis in an implanted cardiac monitoring and treatment device such as an implantable cardioverter defibrillator. In illustrative examples, sensed data including detected events is analyzed to identify likely overdetection of cardiac events. In some illustrative examples, when overdetection is identified, data may be modified to correct for overdetection, to reduce the impact of overdetection, or to ignore overdetected data.

Abstract: A medical device and associated method obtaining cardiac event intervals corresponding to a tachycardia interval. Evidence of a rhythm breaking point is obtained in response to sensing a cardiac event having a morphology corresponding to a supraventricular beat. A non-treatable rhythm is detected in response to the plurality of cardiac event intervals and the evidence of the rhythm breaking point.

Abstract: A system for heart performance characterization and abnormality detection includes an interface for receiving sampled data representing an electrical signal indicating electrical activity of a patient heart over multiple heart beat cycles. A signal processor automatically, decomposes the received sampled data to multiple different subcomponent signals in the time domain. The signal processor associates individual decomposed subcomponents with corresponding different cardiac rotors and determined characteristics of the subcomponents indicating relative significance of the rotors in a cardiac atrial condition. A reproduction device provides data indicating the subcomponent characteristics indicating relative significance of the rotors in a cardiac atrial condition.

Abstract: Systems and methods for determining whether there is a correlation between arrhythmias and myocardial ischemic episodes are provided. An implantable system (e.g., a monitor, pacemaker or ICD) is used to monitor for arrhythmias and to monitor for myocardial ischemic episodes. When such events are detected by the implantable system, the implantable system stores (e.g., in its memory) data indicative of the detected arrhythmias and data indicative of the detected myocardial, ischemic episodes. Then, for each detected arrhythmia, a determination is made based on the data, whether there was a myocardial ischemic episode detected within a specified temporal proximity of (e.g., within a specified amount of time of) the arrhythmia. Where a myocardial ischemic episode occurred within the specified temporal proximity of an arrhythmia, data for the two events can be linked.

Abstract: Systems and devices to gather data from a subject's heart, analyze said data to determine whether the subject is experiencing cardiac arrhythmia, and display results of said determining. Use, and display of cardiac condition information, are preferably simple and unambiguous to untrained users.

Abstract: Atrial fibrillation is detected in an electrical signal representative of a beating heart by measuring atrial activity over a time window of three or more beats, measuring beat interval variation over the time window and combining the measures of atrial activity and beat interval variation to produce an indication of an atrial fibrillation condition in the electrical signal.

Abstract: The present disclosure is directed to the classification of cardiac episodes using an algorithm. In various examples, an episode classification algorithm evaluates electrogram signal data using a probabilistic ventricular oversensing algorithm. The algorithm may look at a plurality of factors weighing for and against a determination of ventricular oversensing. In some examples, the algorithm may also determine whether the cardiac episode includes atrial sensing issues.

Abstract: A method of evaluating an electrophysiological signal is disclosed. A mathematical reconstruction over at least one cycle of the electrophysiological signal is used to identify an abnormal substrate. A non-transitory computer readable medium is also disclosed. The nontransitory computer readable medium has stored thereon instructions for identifying a pathological substrate from a mathematical reconstruction of an electrophysiological signal, which, when executed by a processor, causes the processor to perform steps comprising using a mathematical reconstruction over many cycles of the electrophysiological signal to identify a pathological state. A system for evaluating an electrophysiological signal includes a processor configured to identify a pathological condition from a mathematical reconstruction of the electrophysiological signal. The system also includes a data input coupled to the processor and configured to provide the processor with the electrophysiological signal.

Abstract: Disclosed is an apparatus and method for ambulatory, real-time detection of Atrial Fibrillation (AF) providing an overall accuracy that refers to detection of AF, irrespective of the duration of AF and beat-to-beat classification.

Abstract: The present disclosure is directed to an electrogram summary. In various examples, a subset of cardiac episodes are selected and displayed based on a set of summary rules. The subset of cardiac episodes includes at least one episode from each of a plurality of episode categories with at least one cardiac episode. In some examples, the order in which the cardiac episodes selected are displayed is based on the set of summary rules. The electrogram summary may include images or information regarding each of the selected cardiac episodes.

Abstract: The present disclosure is directed to generating and displaying an electrogram (EGM) summary for use by physicians or other clinicians. An implantable medical device (IMD) transmits EGM signal data for a number of cardiac episodes to an external computing device. The external computing device selects a subset of the cardiac episodes for which information or images are displayed to the user. In various examples, cardiac episodes may be selected for display based at least in part on a retrospective analysis classification of the cardiac episode.

Abstract: A system and method provide for detecting atrial arrhythmias within an implantable medical device capable of sensing and pacing at least an atrium of a heart. Arrhythmia of the atrium is detected. In response to detecting atrial arrhythmia, delivery of pacing signals to the atrium is inhibited under certain conditions. While delivery of the pacing signals to the atrium is inhibited, the detected arrhythmia of the atrium is confirmed during a period of further evaluation. Delivery of pacing signals to the atrium is enabled upon ceasing of the atrial arrhythmia. Inhibiting delivery of the pacing signals during atrial arrhythmia evaluation advantageously provides for an increase in the rate at which the detected arrhythmia is confirmed.

Abstract: The present disclosure is directed to the classification of cardiac episodes using an algorithm. In various examples, an episode classification algorithm evaluates electrogram signal data collected by an implantable medical device. The episode classification algorithm may classify may include a sinus template and a comparison of the electrogram signal to the sinus template. Possible classifications of the cardiac episode may include, for example, unknown, inappropriate, appropriate, supraventricular tachycardia, ventricular tachycardia, ventricular fibrillation or ventricular over-sensing.

Abstract: The present disclosure is directed to the classification of cardiac episodes using an algorithm. In various examples, an episode classification algorithm evaluates electrogram signal data from a near-field channel and a far-field channel. The episode classification algorithm classifies the cardiac episode based on the evaluation of the electrogram signal data for at least one of the near-field and far-field channels. In some examples, a cardiac episode being classified may be an episode that resulted in treatment being provided by an implantable medical device. Possible classifications of the cardiac episode may include, for example, unknown, inappropriate, appropriate, supraventricular tachycardia, ventricular tachycardia, ventricular fibrillation or ventricular over-sensing.

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.