Entries |
Document | Title | Date |
20080215109 | Cardiac rhythm management system with prevention of double counting of events - A cardiac rhythm management system recognizes patterns of interval durations, distinguishing between events in different heart chambers even though signals associated with those different heart chambers are processed using a commonly shared sensing circuit. A therapy delivery algorithm ignores intervals between cardiac events occurring in different heart chambers when determining a cardiac rate upon which the delivery of therapy is based. This reduces the risk of inappropriate delivery of therapy to the patient. Delayed conduction left ventricular beats are not erroneously recognized as a subsequent right ventricular beat, preventing such short intervals from inappropriately triggering a defibrillation countershock. | 09-04-2008 |
20080269823 | Apparatus and Methods for Automatic Determination of a Fusion Pacing Pre-Excitation Interval - Automated adjustment of a pre-excitation interval (PEI) used to deliver hemodynamically efficient fusion pacing therapy. | 10-30-2008 |
20080269824 | System and method for timing synchronized pacing - A device and method for cardiac rhythm management in which a heart chamber is paced in accordance with sense signals from the opposite chamber or other distant cardiac site. The method is particularly useful in delivering cardiac resynchronization therapy. | 10-30-2008 |
20080294216 | Implantable Cardiac Stimulator , System, Device and Method for Monitoring Cardiac Synchrony - In a system and method for monitoring cardiac synchrony in a human heart, a first sensor is positioned at a first cardiac wall location of a heart that is subject to movements related to longitudinal valve plane movements along the longitudinal axis of the heart, and the first sensor measures said cardiac wall movements at the first cardiac wall location and emits a first sensor output signal corresponding thereto, a second sensor is positioned at a second cardiac wall location of the heart that is subject to movements related to longitudinal valve plane movements along the longitudinal axis of the heart, and the second sensor measures the cardiac wall movements at the second cardiac wall location and emits a second sensor output signal corresponding thereto. A lead arrangement is electrically connected to the first and second sensors and conducts the first and second sensor output signals therefrom to processing circuitry that processes the first and second sensor output signals to produce a synchronization signal therefrom indicative of synchrony in the respective valve plane movements at the first and second cardiac wall locations. | 11-27-2008 |
20090005830 | Endocardial Pacing Relating to Conduction Abnormalities - Various systems, methods and arrangements are implemented in connection with ventricular pacing. One such method relates to a method for use in connection with ventricular pacing of a left ventricle of a heart from a pacing lead located in the right ventricle. Ventricular function of the heart is sensed. The sensed ventricular function is used to determine whether a conduction abnormality exists. The ventricular pacing is provided in response to determining a conduction abnormality exists and the ventricular pacing is inhibited in response to determining a conduction abnormality does not exist. | 01-01-2009 |
20090036941 | CARDIAC RESYNCHRONIZATION THERAPY FOR PATIENTS WITH RIGHT BUNDLE BRANCH BLOCK - An implantable medical device and associated method deliver cardiac resynchronization therapy in a patient having right bundle branch block by measuring an interval between a right atrial depolarization and a first heart sound and selecting a right atrial-ventricular (AV) pacing interval in response to the measured interval. Pacing pulses are delivered to the right ventricle of a patient's heart at the selected right AV pacing interval to synchronize the right ventricle with an intrinsic left ventricle depolarization. | 02-05-2009 |
20090043350 | SYSTEM AND METHOD FOR MANAGING REFRACTORY PERIODS IN A CARDIAC RHYTHM MANAGEMENT DEVICE WITH BIVENTRICULAR SENSING - A method and system for managing refractory periods in a cardiac rhythm management device configured for biventricular or biatrial sensing. Refractory periods for each channel of the pacemaker are provided by interval timers that are triggered by sensed or paced events in order to prevent misinterpretation of sensing signals. | 02-12-2009 |
20090088814 | HEART STIMULATING SYSTEM - Heart stimulating system for stimulating at least a ventricle of a heart including: stimulation pulse generator adapted to generate stimulation pulses and connected to a ventricular stimulation electrode for delivering stimulation pulses, atrial sensing stage connected to an electrode for picking up potentials inside an atrium and adapted to sense an excitation or contraction of atrial myocardium, ventricular sensing stage connected to an electrode for picking up potentials inside a ventricle and adapted to sense an excitation or contraction of ventricular myocardium, memory for AV-delay values, a control unit adapted to trigger said stimulation pulse generator to generate ventricular stimulation pulses timed based on AV-delay values stored in said memory and to acquire atrioventricular interval samples, and atrioventricular interval timing analyzing unit for receiving atrioventricular interval samples from said control unit and adapted to generate at least one histogram based on said atrioventricular interval samples and analyze said histograms. | 04-02-2009 |
20090093860 | AUTOMATIC DETERMINATION OF T-SHOCK VULNERABLE WINDOW - A method and apparatus for determining a T-wave shock interval sense a cardiac electrogram (EGM) signal comprising a T-wave signal. A T-wave center is determined from the EGM signal, and a T-wave shock interval is determined in response to determining the T-wave center. A T-wave shock is delivered at the T-wave shock interval computed based on the T-wave center. | 04-09-2009 |
20090099618 | Apparatus and Method for Delivering Electrical Signals to a Heart - Devices, systems and methods for controlling (inhibiting or enabling) the delivery of electrotherapeutic signals to a heart using sensing of local and/or global ECG signals to detect ventricular arrhythmia or indication of possible ventricular arrhythmia in the heart. The devices, systems and methods process the sensed signals and are capable of delivering electroptherapeutic signals to the heart in the presence of a supra-ventricular arrhythmia such as atrial fibrillation and atrial flutter, while inhibiting the delivering electroptherapeutic signals in the presence of PVCs and/or extopic beats, and/or ventricular arrhythmia. The electrotherapeutic signals may include, among others, pacing signals and cardiac contractility modulating signals. | 04-16-2009 |
20090125077 | BIVENTRICULAR CARDIAC STIMULATOR - An implantable cardiac stimulator ( | 05-14-2009 |
20090192562 | CARDIAC RESYNCHRONIZATION VIA LEFT VENTRICULAR PACING - The invention is directed to techniques for providing cardiac resynchronization therapy by synchronizing delivery of pacing pulses to the left ventricle with intrinsic right ventricular depolarizations. An implantable medical device measures an interval between an atrial depolarization and an intrinsic ventricular depolarization is measured. In various embodiments, the intrinsic ventricular depolarization may be an intrinsic right or left ventricular depolarization. The implantable medical device delivers pacing pulses to the left ventricle to test a plurality of pacing intervals. The pacing intervals tested may be within a range around the measured interval between the atrial depolarization and the intrinsic ventricular depolarization. One of the pacing intervals is selected based on a measured characteristic of an electrogram that indicates ventricular synchrony. For example, the pacing interval may be selected based on measured QRS complex widths and/or Q-T intervals. The implantable medical device paces the left ventricle based on the selected pacing interval. | 07-30-2009 |
20090204167 | Assessment of ischemia, and risk of sudden cardiac death, VIA heart-functionality parameter and acoustic cardiographic monitoring - A method for assessing, and applying therapy in relation to, degree of ischemia and risk for sudden cardiac death in a therapy-device-equipped subject utilizing a Holter-type instrumentality, including (a) gathering simultaneous ECG and heart-sound data, (b) computer processing and interrelating the gathered data to obtain one or more heart-functionality parameter(s), such as LDPT, and (c) using the obtained parameter(s), adjusting, as necessary, the therapy device in a manner designed to minimize and counteract the likelihood of the onset or advancement of ischemia, and/or the onset of sudden cardiac death. Computer processing involves (1) calculating a real-time, acoustic cardiographic therapy (AC) value based on the obtained heart-functionality parameter(s), (2) comparing that calculated AC value to a pre-established, reference AC value to detect differences therebetween, and (3) performing therapy-device adjustment, as necessary so as to minimize such differences. | 08-13-2009 |
20090259271 | Methods and Devices for Accurately Classifying Cardiac Activity - Methods, systems, and devices for signal analysis in an implanted cardiac monitoring and treatment device such as an implantable cardioverter defibrillator. In illustrative examples, captured 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. New methods for organizing the use of morphology and rate analysis in an overall architecture for rhythm classification and cardiac signal analysis are also discussed. | 10-15-2009 |
20090275999 | EXTRA-CARDIAC IMPLANTABLE DEVICE WITH FUSION PACING CAPABILITY - According to this disclosure, a non-transvenous pacing and, optionally defibrillation, therapy device is implanted subcutaneously and oriented to provide cardiac sensing from electrodes spaced from a heart and deliver pacing and/or defibrillation from one or more non-transvenous electrodes (e.g., an epicardial or pericardial electrode or electrode patch). A subject receiving a device according to this disclosure is monitored to confirm a relatively stable bundle branch block (i.e., delayed activation) of one ventricle. The subcutaneous device has electrodes disposed on the housing and/or having an electrode on a subcutaneous medical lead is oriented so that the pacing (and sensing) vector impinges mainly upon the one ventricle, and/or optionally an epicardial or pericardial lead is deployed to a last-to-depolarize ventricle (e.g., a left ventricle) so that single-ventricular pacing is delivered to achieve fusion depolarization of both ventricles. | 11-05-2009 |
20090281590 | Method and Apparatus to Ensure Consistent Left Ventricular Pacing - A method of operating a cardiac therapy system to deliver cardiac resynchronization therapy (CRT) pacing that includes pacing both ventricles or pacing only the left ventricle is described. Delivery of the CRT pacing to one or both ventricles is scheduled for a cardiac cycle. If an intrinsic depolarization of a ventricle is detected during a pacing delay of the ventricle, then the scheduled CRT pacing to the ventricle is inhibited for the cycle. The intrinsic interval of the ventricle, such as the intrinsic atrioventricular interval concluded by the intrinsic depolarization, is measured. During a subsequent cardiac cycle, the pacing delay of the ventricle is decreased to be less than or equal to the measured intrinsic interval. Capture of the ventricle is verified after pacing is delivered during the subsequent cardiac cycle. | 11-12-2009 |
20090281591 | SMART DELAY FOR INTERMITTENT STRESS THERAPY - A pacing system delivers cardiac protection pacing to protect the heart from injuries. The pacing system receives a set of inputs and calculates parameters for delivering optimized cardiac protection pacing tailored for different stress levels. The system automatically adjusts heart rate to optimize cardiac protection pacing in a closed-loop system. In one embodiment, a method for delivering pacing pulses for cardiac protection is provided. Intrinsic atrioventricular (AV) intervals are sensed. The intrinsic AV interval and a predetermined equation relating the AV interval to an optimal AV delay are used to provide a maximum positive rate of left ventricular pressure change during systole. An AV delay is calculated using a predetermined percentage of the optimal AV delay to deliver ventricular pacing pulses to provide a desired level of stress for cardiac protective pacing therapy (CPPT) to provide a cardiac conditioning therapy to improve autonomic balance. | 11-12-2009 |
20100069990 | SYSTEM AND METHOD FOR DETERMINING ATRIOVENTRICULAR PACING DELAY BASED ON ATRIAL REPOLARIZATION - Techniques are provided for estimating optimal atrioventricular pacing delay values for use in pacing the ventricles based on features of an intracardiac electrogram (IEGM) signal. Briefly, atrioventricular pacing delay pacing values are set based upon the location of atrial repolarization events within the IEGM. In one example, the end of an atrial repolarization is identified, then the interval from the atrial depolarization to the end of the atrial repolarization is measured. The atrioventricular pacing delay is then set by subtracting an offset value from that interval so as to time delivery of V-pulses prior the end of atrial repolarization. In this manner, atrioventricular pacing delay values are set based only IEGM signals and hence can be set to optimal/preferred values by the device itself without requiring surface electrocardiogram (EKG) signals and Doppler echocardiography or other cardiac performance monitoring techniques. | 03-18-2010 |
20100087888 | Methods and Apparatuses for Cardiac Resynchronization Therapy Mode Selection Based on Intrinsic Conduction - Systems and methods for selecting a cardiac resynchronization therapy (CRT) mode involve sensing electrocardiogram (ECG) data for a patient, identifying a PR interval from the sensed ECG data, comparing the PR interval to a threshold, and selecting a CRT mode by selecting between a synchrony optimization mode and a preload optimization mode, the selection based on the comparison of the PR interval to the threshold. A synchrony optimization mode may be selected if the parameter is less than the threshold, and may optimize CRT for fusion between a left ventricular pulse and an intrinsic wavefront. The preload optimization mode may be selected if the parameter is greater than the threshold, and may optimize CRT for fusion between respective wavefronts of the left ventricular pace and a right ventricular pace. | 04-08-2010 |
20100087889 | Dynamic Cardiac Resynchronization Therapy by Tracking Intrinsic Conduction - Systems and methods for pacing the heart using resynchronization pacing delays that achieve improvement of cardiac function are described. An early activation pacing interval is calculated based on an optimal AV delay and an atrial to early ventricular activation interval between an atrial event and early activation of a ventricular depolarization. The early activation pacing interval for the ventricle is calculated by subtracting the measured AV | 04-08-2010 |
20100114231 | METHODS AND SYSTEMS TO MONITOR ISCHEMIA - An implantable medical device includes leads, a segment monitoring module, an impedance detection module and an ischemia module. The leads include electrodes that are configured to be positioned within a heart and that are capable of sensing cardiac signals having a segment of interest. The segment monitoring module determines segment variations of the segment of interest in the cardiac signals. The impedance detection module measures impedance vectors between predetermined combinations of the electrodes. The ischemia detection module monitors ischemia based on changes in the segment variations of the segment of interest and based on changes in the impedance vectors. | 05-06-2010 |
20100121401 | OPTIMIZATION OF CARDIAC PACING THERAPY BASED ON PACED PROPAGATION DELAY - An exemplary method includes delivering stimulation energy via a right ventricular site; sensing an evoked response caused by the delivered stimulation energy at the right ventricular site; calculating a paced propagation delay for the right ventricular site (PPD | 05-13-2010 |
20100121402 | REVERSE HYSTERESIS AND MODE SWITCHING FOR INTERMITTENT PACING THERAPY - Cardioprotective pre-excitation pacing may be applied to stress or de-stress a particular myocardial region delivering of pacing pulses in a manner that causes a dyssynchronous contraction. Such dyssynchronous contractions are responsible for the desired cardioprotective effects of pre-excitation pacing. A method and device for applying reverse hysteresis and mode switching to the delivery of such cardioprotective pacing are described. | 05-13-2010 |
20100137933 | CARDIAC RHYTHM MANAGEMENT SYSTEM WITH OPTIMIZATION OF CARDIAC PERFORMANCE USING HEART RATE - A method of optimizing inter-site delay is disclosed for a cardiac rhythm management device that includes a dual chamber pacemaker, especially designed for treating congestive heart failure by pacing a plurality of sites. A microcontroller is operative to adjust the pacing mode and inter-site delay of the pacemaker so as to achieve optimum hemodynamic performance. Atrial cycle lengths measured during transient (immediate) time intervals following a change in the mode inter-site delay are signal processed and a determination can then be made as to which particular configuration yields the optimum performance. Performance is optimized when the patient is at rest and when the patient exercises so that a rate-adapted dynamic value of the optimum performance can be applied. | 06-03-2010 |
20100145405 | Systems and Methods for Controlling Ventricular Pacing in Patients with Long Inter-Atrial Conduction Delays - Techniques are provided for use by implantable medical devices for controlling ventricular pacing. In one example, optimal atrio-ventricular and interventricular pacing delay values are determined for pacing the heart of the patient based, in part, on a measured inter-atrial conduction delay. Atrio-ventricular conduction delays are then measured within the patient. The atrio-ventricular pacing delays are compared with the measured atrio-ventricular conduction delays. If the atrio-ventricular pacing delays are less than the measured atrio-ventricular conduction delays, biventricular pacing is delivered using the atrio-ventricular pacing delay and the interventricular pacing delay. However, if the atrio-ventricular pacing delays are not less than the corresponding atrio-ventricular conduction delays, as can occur if the inter-atrial conduction delay is large, then alternative pacing regimes are selectively enabled, such as monoventricular pacing in the chamber having the longer conduction delay value, biventricular pacing with negative hysteresis, or biventricular pacing with pacing delays reduced using predetermined offset values. | 06-10-2010 |
20100222840 | SYSTEM AND METHOD OF AV INTERVAL SELECTION IN AN IMPLANTABLE MEDICAL DEVICE - An implantable medical device provides ventricular pacing capabilities and optimizes AV intervals for multiple purposes. In general, intrinsic conduction is promoted by determining when electromechanical systole (EMS) ends and setting an AV interval accordingly. EMS is determined utilizing various data including QT interval, sensor input, and algorithmic calculations. | 09-02-2010 |
20110022110 | SYSTEMS AND METHODS FOR OPTIMIZING VENTRICULAR PACING DELAYS FOR USE WITH MULTI-POLE LEADS - Techniques are provided for use by implantable medical devices for controlling ventricular pacing using a multi-pole left ventricular (LV) lead. In one example, a single “V sense” test is performed to determine intrinsic interventricular conduction time delays (Δ | 01-27-2011 |
20110022111 | SYSTEMS AND METHODS FOR OPTIMIZING VENTRICULAR PACING DELAYS DURING ATRIAL FIBRILLATION - Techniques are provided for use by implantable medical devices for controlling ventricular pacing, particularly during atrial fibrillation. In one example, during a V sense test for use in optimizing ventricular pacing, the implantable device determines relative degrees of variation within antecedent and succedent intervals detected between ventricular events sensed on left ventricular (LV) and right ventricular (RV) sensing channels. Preferred or optimal ventricular pacing delays are then determined, in part, based on a comparison of the relative degrees of variation obtained during the V sense test. In another example, during RV and LV pace tests, the device distinguishes QRS complexes arising due to interventricular conduction from QRS complexes arising due to atrioventricular conduction from the atria, so as to permit the determination of correct paced interventricular conduction delays for the patient. The paced interventricular conduction delays are also used to optimize ventricular pacing. Biventricular and monoventricular pacing regimes are provided. | 01-27-2011 |
20110022112 | SYSTEMS AND METHODS FOR DETERMINING VENTRICULAR PACING SITES FOR USE WITH MULTI-POLE LEADS - Techniques are provided for use by implantable medical devices for controlling multi-site left ventricular (MSLV) pacing using a multi-pole left ventricular (LV) lead. In various examples, a reduced number of “V sense”, “RV pace”, and “LV pace” tests are performed to determine preferred or optimal interventricular pacing delays (VV) for use with MSLV pacing. Additionally, techniques are described for sorting the order by which LV sites are to be paced during MSLV pacing. Furthermore, techniques are described for detecting and addressing circumstances where AV/PV delays are longer than corresponding AR/PR delays during MSLV. | 01-27-2011 |
20110029035 | VENTRICULAR CARDIAC STIMULATOR - An implantable cardiac stimulator includes at least one first sensing unit for detecting intrinsic cardiac activities of a first ventricle, at least one ventricular stimulation unit for stimulating a second ventricle, and a stimulation control unit connected to the first sensing unit. The stimulation unit processed output signals of the first sensing unit and generates control signals for the stimulation units. The stimulation control unit derives a current intrinsic RR interval from detected ventricular intrinsic cardiac activities R of the first ventricle, and to determine from the RR interval a delay interval Δ, which begins with a ventricular event of the first ventricle and at the end of which the stimulation control unit triggers a stimulation of the second ventricle (unless it is suppressed). | 02-03-2011 |
20110082513 | CARDIAC RHYTHM MANAGEMENT SYSTEM WITH MAXIMUM TRACKING RATE (MTR) HYSTERESIS - A cardiac rhythm management system provides both a safe maximum pacing rate limit and a physiological maximum pacing rate limit. In one embodiment, a normal maximum tracking rate (MTR) and a hysteresis MTR are provided. The hysteresis MTR is set higher than the normal MTR and functions as a maximum pacing rate. When an atrial rate exceeds the hysteresis MTR limit, the maximum pacing rate limit is set to the normal MTR. Once the atrial rate falls below a predetermined threshold, the maximum pacing rate limit is set to the hysteresis MTR. This provides for a more rapid and natural maximum pacing rate limit for a patient, while still protecting the patient from being paced at abnormally high rates. | 04-07-2011 |
20110098769 | MINIMUM VENTRICULAR PACING TO BREAK THE REPETITIVE AR-VS PATTERN - An implantable cardiac pacing device delivering minimum ventricular pacing and an associated method control intervals timed by the device during sensing and pacing. An atrial-only pacing mode is set in response to sensing intrinsic ventricular events in the ventricular chamber. A first post-ventricular atrial refractory period is set following each of a plurality of ventricular events sensed in the ventricular chamber, and atrial events each being sensed during first post-ventricular atrial refractory periods are detected. A second post-ventricular atrial refractory period is set in response to detecting the atrial events each being sensed during the first post-ventricular atrial refractory period. | 04-28-2011 |
20110098770 | SYSTEMS AND METHODS FOR OPTIMIZING MULTI-SITE LEFT VENTRICULAR PACING BASED ON INTERELECTRODE CONDUCTION DELAYS - Techniques are provided for use with an implantable cardiac stimulation device equipped for multi-site left ventricular (MSLV) pacing using a multi-pole LV lead. In one example, MSLV interelectrode conduction delays are determined among the electrodes of the multi-pole LV lead. MSLV interelectrode pacing delays are then set based on the MSLV interelectrode conduction delays for use in delivering MSLV pacing. To this end, various criteria are exploited for determining optimal values for the pacing delays based on the interelectrode conduction delays. MSLV pacing is then controlled using the specified MSLV interelectrode pacing delays. In some examples, the optimization procedure is performed by the implantable device itself. In other examples, the procedure is performed by an external programmer device. In such an embodiment, the external device determines optimal MSLV interelectrode pacing delays and then transmits programming commands to the implantable device to program the device to use the pacing delays. | 04-28-2011 |
20110106202 | METHOD AND SYSTEM FOR SETTING CARDIAC RESYNCHRONIZATION THERAPY PARAMETERS - A method or system for computing and/or setting optimal cardiac resynchronization pacing parameters as derived from intrinsic conduction data is presented. The intrinsic conduction data includes intrinsic atrio-ventricular and interventricular delay intervals which may be collected via the sensing channels of an implantable cardiac device. Among the parameters which may be optimized in this manner are an atrio-ventricular delay interval and a biventricular offset interval. In one of its aspects, the invention provides for computing optimum pacing parameters for patients having some degree of AV block or with atrial conduction deficits. Another aspect of the invention relates to a pacing mode and configuration for providing cardiac resynchronization therapy to patients with a right ventricular conduction disorder. | 05-05-2011 |
20110112596 | SYSTEM AND METHOD FOR DETERMINING INTRINSIC AV INTERVAL TIMING - An atrial based pacing protocol promotes intrinsic conduction. An entire cardiac cycle is monitored for ventricular activity and permitted to lapse with ventricular activity. Ventricular pacing is available in a cardiac cycle immediately subsequent to such a skipped beat. When monitoring for intrinsic ventricular events, an event is expected within a given window. If no such event is detected, the cardiac cycle is truncated, leading to a shorter cycle that is devoid of ventricular activity. The subsequent cycle has a high likelihood of a ventricular sensed event and a greater than normal AV interval is provided prior to pacing. | 05-12-2011 |
20110137368 | EXPERT SYSTEM AND METHOD - A medical device programmer and a method of operation in which a first data value is received and used in the execution of one or more algorithms. One or more suggested pulse generator settings are calculated from the one or more algorithms based on the first data value, and the one or more suggested pulse generator settings are displayed on an interactive display screen of the medical device programmer. In one embodiment, the first data value is a duration interval of a QRS complex. From the duration interval, suggestions are made as to one or more ventricular chambers in which to provide pacing pulses. Additionally, pacing intervals for an AV delay are suggested based on measured P-R intervals, or pacing intervals for an LV offset are suggested based on a measured duration interval of a V-V-interval between a right ventricular event and a left ventricular event. | 06-09-2011 |
20110152964 | SYSTEM AND METHOD OF AV INTERVAL SELECTION IN AN IMPLANTABLE MEDICAL DEVICE - An implantable medical device provides ventricular pacing capabilities and optimizes AV intervals for multiple purposes. In general, intrinsic conduction is promoted by determining when electromechanical systole (EMS) ends and setting an AV interval accordingly. EMS is determined utilizing various data including QT interval, sensor input, and algorithmic calculations. | 06-23-2011 |
20110172731 | METHODS AND APPARATUS TO STIMULATE HEART ATRIA - A method and apparatus for treatment of hypertension and heart failure by increasing vagal tone and secretion of endogenous atrial hormones by excitory pacing of the heart atria. Atrial pacing is done during the ventricular refractory period resulting in atrial contraction against closed AV valves, and atrial contraction rate that is higher than the ventricular contraction rate. Pacing results in the increased atrial wall stress. An implantable device is used to monitor ECG and pace the atria in a nonphysiologic manner. | 07-14-2011 |
20110178567 | TECHNIQUES FOR PROMOTING BIVENTRICULAR SYNCHRONY AND STIMULATION DEVICE EFFICIENCY USING INTENTIONAL FUSION - A method includes providing an optimal interventricular interval, determining an atrio-ventricular conduction delay for the ventricle having faster atrio-ventricular conduction, determining an interventricular conduction delay and determining an advance atrio-ventricular pacing interval, for use in pacing the ventricle having slower atrio-ventricular conduction, based at least in part on the optimal interventricular interval and the interventricular conduction delay. | 07-21-2011 |
20110190841 | APPARATUS AND METHODS OF OPTIMIZING ATRIOVENTRICULAR PACING DELAY INTERVALS - Provided herewith are methods and apparatus for optimizing an atrioventricular (AV) pacing delay interval based upon ECG-based optimization is calculated as a linear function of P-wave duration, sensed PR (intrinsic) interval, sensed or paced QRS duration and heart rate. Since the relationship among these parameters is linear, once the coefficients are solved (which can be any value, including null) with reference to a known optimized AV interval (AVopt) such as from an echocardiographic study, an AVopt value can be dynamically adjusted in an ambulatory subject. The various combinations of values can be loaded into a look up table or calculated automatically. And, since some of the parameters do not typically change much over time they can be determined acutely and fed into the equation while the other values can be measured frequently. The parameter values can be measured by an implantable medical device such as a dual- or triple-chamber pacemaker. | 08-04-2011 |
20110202103 | WAKEUP OF IMPLANTABLE COMMUNICATION CIRCUITRY - An IMD has its communication circuitry in an inactive state and has access to two different identifier codes. The IMD activates the communication circuitry based on reception of a wakeup message that includes an identifier code that is identical to the identifier code currently assigned to the IMD. A communication device generates and transmits first wakeup messages that include a first identifier code associated with the IMD and second wakeup messages that include a second identifier code associated with the IMD. Depending on the currently assigned identifier code of the IMD the IMD will respond to either first or second wakeup messages. | 08-18-2011 |
20110251655 | APPARATUS AND METHOD FOR OPTIMIZING ATRIOVENTRICULAR DELAY - Systems and methods to optimize atrioventricular delay during sensing or pacing of the atrium and for a plurality of sensed rates or pacing rates. In one example, a paced atrioventricular delay is calculated using a sensed atrioventricular interval and a paced atrioventricular interval. In another example, a plurality of paced atrioventricular delays for different pacing rates can be calculated. In another example embodiment, a plurality of sensed atrioventricular delays for different sensing rates can be calculated. Combinations of the various systems and methods are also possible. | 10-13-2011 |
20110257698 | METHOD FOR EXCLUSION OF ECTOPIC EVENTS FROM HEART RATE VARIABILITY METRICS - Heart rate variability metrics are derived from the intervals between successive heart beats, referred to as BB intervals. A method implementable by an implantable cardiac device for excluding BB intervals due to ectopic beats based on a function of preceding BB intervals is presented. It is desirable to remove such BB intervals from a BB interval time series used to calculate a heart rate variability metric. | 10-20-2011 |
20110264159 | METHODS FOR OPTIMIZATION OF BIVENTRICULAR PACING DEVICES AND SYSTEMS USEFUL THEREFOR - The invention is directed to methods and devices for optimization of biventricular pacing in subjects suffering from heart failure. The invention provides for a method for selection of optimal parameters for permanent pacing, the method comprising: positioning one or more arrays of lead wires in the posterior pericardium of a subject, wherein the arrays are connected to a multiplexing switch, wherein the switch is connected to a computer processor and a biventricular pacemaker, from the computer processor, generating a randomized sequence of: (i) pacing sites (VPS), (ii) right ventricular-left ventricular delays (RLDs), (iii) heart rates (HR); (iv) atrioventricular delays (AVDs), (v) or any combination or permutation thereof; and determining cardiac output in real time, using aortic flow velocity, thereby allowing selection of optimal parameters for permanent pacing. | 10-27-2011 |
20110276105 | REFRACTORY PERIOD MANAGEMENT BASED ON DETECTION OF AN EVOKED RESPONSE - Various approaches are described for managing refractory periods based on the detection of an evoked response. The heart is paced and an evoked response is detected. At least one refractory period is adapted based on the detected evoked response. Adapting the refractory period may involve, for example, initiating a refractory period, terminating a refractory period, extending a refractory period or modifying one or more parameters of the refractory period. Adapting the refractory period may involve modifying a sensing threshold based on the detected evoked response. The sensing threshold of an atrial sensing channel may be adjusted, for example, to avoid sensing a ventricular evoked response on the atrial channel while allowing sensing of a P-wave on the atrial channel. | 11-10-2011 |
20110301661 | Atrial Tachyarrhymia Detection System And Method - 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. | 12-08-2011 |
20110307026 | SYSTEMS, DEVICES AND METHODS FOR MONITORING EFFICIENCY OF PACING - Various systems, methods, devices and arrangements are implemented for use in pacing of the heart. One implementation is directed to methods and systems for determining a pacing location in the right ventricle of a heart and near the His bundle. A pacing signal is delivered to the location in the right ventricle. The pacing signal produces a capture of a left ventricle. Properties of the capture are monitored. Results of the monitored capture are used to assess the effectiveness of the delivered pacing signal as a function of heart function. The heart function can be, for example, at least one of a QRS width, fractionation and a timing of electrical stimulation of a late activation site of a left ventricle relative to the QRS. | 12-15-2011 |
20110319956 | SYSTEMS, DEVICES AND METHODS RELATING TO ENDOCARDIAL PACING FOR RESYNCHRONIZATION - Disclosed are certain methods, apparatus, and processor-readable mediums that may be used to treat a conduction abnormality of the heart. In one example, the apparatus includes an implantable pacing profile generator configured to generate a specified pacing electrostimulation profile for delivery to a heart via electrodes located near a septal region of the right ventricle of the heart near the His bundle, the pacing profile including a first pulse for delivery via a first electrode; and a second pulse for delivery via a second electrode; and wherein the first and second pulses are at least partially concurrent in time and opposite in polarity to each other. | 12-29-2011 |
20120004697 | NON-LINEAR DYNAMIC AV DELAY - A non-linear dynamic specified AV delay can be used, such as to help maintain cardiac resynchronization therapy, such as in patients with one or more symptoms of congestive heart failure. | 01-05-2012 |
20120004698 | PHYSIOLOGIC DEMAND DRIVEN PACING - Physiologic demand driven pacing can be used to maintain cardiac synchrony and improve hemodynamic function in patients with heart failure. | 01-05-2012 |
20120071944 | IDENTIFICATION AND REMEDIATION OF OVERSENSED CARDIAC EVENTS USING FAR-FIELD ELECTROGRAMS - In general, the disclosure is directed to techniques for identification and remediation of oversensed cardiac events using far-field electrograms (FFEGMs). Identification of oversensed cardiac events can be used in an ICD to prevent ventricular fibrillation (VF) detection, and thereby avoid delivery of an unnecessary defibrillation shock. Alternatively, or additionally, identification of oversensed cardiac events can be used in an ICD to support delivery of bradycardia pacing during an oversensing condition. In some cases, bradycardia pacing delivered in response to detection of oversensed cardiac events may include pacing pulses from multiple vectors to provide redundancy in the event the oversensing may be due to a lead-related condition. | 03-22-2012 |
20120083854 | EXPERT SYSTEM AND METHOD - A medical device programmer and a method of operation in which a first data value is received and used in the execution of one or more algorithms. One or more suggested pulse generator settings are calculated from the one or more algorithms based on the first data value, and the one or more suggested pulse generator settings are displayed on an interactive display screen of the medical device programmer. In one embodiment, the first data value is a duration interval of a QRS complex. From the duration interval, suggestions are made as to one or more ventricular chambers in which to provide pacing pulses. Additionally, pacing intervals for an AV delay are suggested based on measured P-R intervals, or pacing intervals for an LV offset are suggested based on a measured duration interval of a V-V-interval between a right ventricular event and a left ventricular event. | 04-05-2012 |
20120101542 | TIMING FOR HIS-BUNDLE PACING - An A-H delay can be specified, such as by computing the A-H delay using a measured cardiovascular physiologic parameter. The A-H delay can be used for specifying timing between a paced or sensed atrial contraction and a His-bundle pacing time. | 04-26-2012 |
20120109245 | CARDIAC THERAPY BASED UPON IMPEDANCE SIGNALS - Methods and/or devices are disclosed herein for monitoring cardiac impedance signal and delivering therapy to a patient's heart based upon the monitored cardiac impedance. | 05-03-2012 |
20120136406 | Systems and Methods for Determining Optimal Atrioventricular Pacing Delays Based on Cardiomechanical Delays - Techniques are provided for use with implantable medical devices such as pacemakers for optimizing atrioventricular (AV) pacing delays for use with cardiac resynchronization therapy (CRT). In one example, the end of atrial mechanical contraction and the onset of isovolumic ventricular mechanical contraction are detected within a patient in which the device is implanted based on cardiomechanical signals, such as cardiogenic impedance (Z) signals, S1 heart sounds or left atrial pressure (LAP) signals. Then, a cardiomechanical time delay (MC_AV) between the end of atrial contraction and the onset of isovolumic ventricular contraction is determined. AV pacing delays are set based on MC_AV to align the end an atrial kick with the onset of isovolumic ventricular contraction. Thereafter, pacing is controlled based on the AV pacing delays. | 05-31-2012 |
20120143277 | CARDIAC RHYTHM MANAGEMENT SYSTEM SELECTING BETWEEN MULTIPLE SAME-CHAMBER ELECTRODES FOR DELIVERING CARDIAC THERAPY - A cardiac rhythm management system selects one of multiple electrodes associated with a particular heart chamber based on a relative timing between detection of a depolarization fiducial point at the multiple electrodes, or based on a delay between detection of a depolarization fiducial point at the multiple electrodes and detection of a reference depolarization fiducial point at another electrode associated with the same or a different heart chamber. Subsequent contraction-evoking stimulation therapy is delivered from the selected electrode. | 06-07-2012 |
20120150254 | AV DELAY FEATURES - An atrial event and a ventricular event can be received, and an atrioventricular (AV) delay can be provided using information about the atrial and ventricular events. The AV delay can be increased after a first condition is satisfied to allow a heart to regain intrinsic control of ventricular activation, and changed after a second condition is satisfied to allow the heart to remain in intrinsic control of ventricular activation. | 06-14-2012 |
20120158087 | REFRACTORY AND BLANKING INTERVALS IN THE CONTEXT OF MULTI-SITE LEFT VENTRICULAR PACING - A refractory period for a pacemaker sensing channel refers to a period of time during which the sensing channel is either blind to incoming electrical signals, termed a blanking interval, and/or during which the device is configured to ignore such signals for purposes of sense event detection. Methods and devices for implementing refractory periods in the context of multi-site left ventricular pacing are described. | 06-21-2012 |
20120158088 | METHOD AND APPARATUS FOR ADJUSTMENT OF SEQUENTIAL BIVENTRICULAR PACING PARAMETERS - A method and system are disclosed for setting the pacing parameters utilized by an implantable cardiac device in delivering cardiac resynchronization therapy. The system may, in different embodiments, be implemented in programming of the implantable device and an external programmer in communication therewith or in the programming of the implantable device by itself. The selection of the pacing parameters is based at least in part upon measurements of intrinsic cardiac conduction parameters. Among the pacing parameters which may be selected in this way are the atrio-ventricular delay interval used in atrial-tracking and AV sequential pacing modes and the biventricular offset interval. | 06-21-2012 |
20120165892 | SYSTEMS AND METHODS FOR OPTIMIZING AV/VV PACING DELAYS USING COMBINED IEGM/IMPEDANCE-BASED TECHNIQUES FOR USE WITH IMPLANTABLE MEDICAL DEVICES - Systems and methods are provided wherein intracardiac electrogram (IEGM) signals are used to determine a set of preliminary optimized atrioventricular (AV/PV) and interventricular (VV) pacing delays. In one example, the preliminary optimized AV/VV pacing delays are used as a starting point for further optimization based on impedance signals such as impedance signals detected between a superior vena cava (SVC) coil electrode and a device housing electrode, which are influenced by changes in stroke volume within the patient. Ventricular pacing is thereafter delivered using the AV/VV pacing delays optimized via impedance. In another example, parameters derived from IEGM signals are used to limit the scope of an impedance-based optimization search to reduce the number of pacing tests needed during impedance-based optimization. Biventricular and multi-site left ventricular (MSLV) examples are described. | 06-28-2012 |
20120165893 | METHOD AND SYSTEM FOR DELIVERING CARDIAC RESYNCHRONIZATION THERAPY WITH VARIABLE ATRIO-VENTRICULAR DELAY - A pacing system computes optimal cardiac resynchronization pacing parameters using intrinsic conduction intervals. In various embodiments, values for atrio-ventricular delay intervals are each computed as a function of an intrinsic atrio-ventricular interval and a parameter reflective of an interventricular conduction delay. Examples of the parameter reflective of the interventricular conduction delay include QRS width and interval between right and left ventricular senses. | 06-28-2012 |
20120165894 | CLOSED LOOP IMPEDANCE-BASED CARDIAC RESYNCHRONIZATION THERAPY SYSTEMS, DEVICES, AND METHODS - This document discusses, among other things, systems, devices, and methods measure an impedance and, in response, adjust an atrioventricular (AV) delay or other cardiac resynchronization therapy (CRT) parameter that synchronizes left and right ventricular contractions. A first example uses parameterizes a first ventricular volume against a second ventricular volume during a cardiac cycle, using a loop area to create a synchronization fraction (SF). The CRT parameter is adjusted in closed-loop fashion to increase the SF. A second example measures a septal-freewall phase difference (PD), and adjusts a CRT parameter to decrease the PD. A third example measures a peak-to-peak volume or maximum rate of change in ventricular volume, and adjusts a CRT parameter to increase the peak-to-peak volume or maximum rate of change in the ventricular volume. | 06-28-2012 |
20120165895 | Non-Captured Intrinsic Discrimination in Cardiac Pacing Response Classification - Cardiac devices and methods discriminate non-captured intrinsic beats during evoked response detection and classification by comparing the features of a post-pace cardiac signal with expected features associated with a non-captured response with intrinsic activation. Detection of a non-captured response with intrinsic activation may be based on the peak amplitude and timing of the cardiac signal. The methods may be used to discriminate between a fusion or capture beat and a non-captured intrinsic beat. Discriminating between possible cardiac responses to the pacing pulse may be useful, for example, during automatic capture verification and/or a capture threshold test. | 06-28-2012 |
20120165896 | FULLY INHIBITED DUAL CHAMBER PACING MODE - A pacing mode is provided, in one embodiment, that permits missed or skipped ventricular beats. The mode monitors a full cardiac cycle (A-A interval) for the presence of intrinsic ventricular activity. If ventricular activity is present, a flag is set that is valid for the next cardiac cycle. At the beginning of the next cardiac cycle, the device determines if the flag is present. So long as the flag is present, the device will not deliver a ventricular pacing pulse in that cycle, even if there is no intrinsic ventricular activity. If there is no flag present at the start of a given cardiac cycle, a ventricular pacing pulse is delivered and this ventricular activity sets a flag for the subsequent cardiac cycle. | 06-28-2012 |
20120185012 | SYSTEMS AND METHODS FOR SELECTIVELY LIMITING MULTI-SITE VENTRICULAR PACING DELAYS DURING OPTIMIZATION OF CARDIAC RESYNCHRONIZATION THERAPY PARAMETERS - Techniques are provided for use with implantable cardiac stimulation devices equipped for multi-site left ventricular (MSLV) cardiac pacing. Briefly, intraventricular and interventricular conduction delays are detected for paced cardiac events. Maximum pacing time delays are determined for use with MSLV pacing where the maximum pacing time delays are set based on the conduction delays to values sufficient to avoid capture problems due to wavefront propagation, such as fusion or lack of capture. MSLV pacing delays are then set to values no greater than the maximum pacing delays and cardiac resynchronization therapy (CRT) is delivered using the MSLV pacing delays. In an example where an optimal interventricular pacing delay (VV) is determined in advance using intracardiac electrogram-based or hemodynamic-based optimization techniques, the optimal value for VV can be used as a limiting factor when determining the maximum MSLV pacing time delays. | 07-19-2012 |
20120185013 | Heart Stimulating Device with Selecting Optimal Electrode Configuration - Heart stimulating device comprising a stimulation pulse generator arranged in a stimulator housing, where the heart stimulating device is coupled to a plurality of stimulation and sensing electrodes arranged at one or many leads, the electrodes being adapted to be arranged in connection with the heart to stimulate the heart. The device further comprises a sensing unit adapted to sense electrical heart tissue responses to applied electrical stimulation pulses via said electrodes. The pulse generator is adapted to generate stimulation pulses to be applied to the heart tissue by different electrodes, and for each of the applied pulses resulting in a depolarization wave in the heart tissue a depolarization wave velocity parameter of the wave is determined by the sensing unit and stored in a memory unit. The stored wave velocity parameters, related to different stimulating electrodes, are compared to each other in a comparison unit and the comparison is used to adapt a stimulation mode when stimulating the heart to optimize the hemodynamic performance of the heart. | 07-19-2012 |
20120197334 | Methods and Devices for Accurately Classifying Cardiac Activity - Methods, systems, and devices for signal analysis in an implanted cardiac monitoring and treatment device such as an implantable cardioverter defibrillator. In some examples, captured 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. Several examples emphasize the use of morphology analysis using correlation to static templates and/or inter-event correlation analysis. | 08-02-2012 |
20120203297 | METHODS AND DEVICES FOR THREE-STAGE VENTRICULAR THERAPY - Methods and apparatus for a three-stage ventricular cardioversion and defibrillation therapy that treats ventricular tachycardia and fibrillation at low energy levels. An implantable therapy generator adapted to generate and selectively deliver a three-stage ventricular therapy and at least two leads operably each having at least one electrode adapted to be positioned proximate the ventricle of the patient. The device is programmed to deliver a three-stage therapy via both a far-field configuration and a near-field configuration of the electrodes upon detection of a ventricular arrhythmia. The three-stage therapy includes a first stage for unpinning of one or more singularities associated with the ventricular arrhythmia, a second stage for anti-repinning of the one or more singularities, both of which are delivered via the far-field configuration of the electrodes, and a third stage for extinguishing of the one or more singularities associated delivered via the near-field configuration of the electrodes. | 08-09-2012 |
20120239105 | ATRIAL NERVE STIMULATION WITH VENTRICULAR PACING - An implantable medical device senses atrial depolarizations having associated refractory periods thereafter and delivers electrical stimulation pulses during the associated refractory periods to stimulate the atrioventricular (AV) node to cause a prolonged conduction time of an atrial depolarization to a ventricular chamber. The device delivers a pacing pulse to a first ventricular chamber during the prolonged conduction time to cause a contraction and associated refractory period of the first ventricular chamber, the first ventricular chamber contraction occurring earlier than a contraction of a second ventricular chamber. | 09-20-2012 |
20120245650 | CARDIAC STIMULATING DEVICE - An implantable medical device, IMD, comprises atrial and ventricular sensing units for sensing atrial or ventricular electric events. The IMD also comprises atrial and ventricular pulse generators for generating atrial or ventricular pacing pulses. The ventricular sensing unit is connectable to a multi-electrode lead to individually sense electric events in a ventricle using multiple electrode pairs implanted at different ventricular sites. A controller blanks the ventricular sensing unit during a blanking period following delivery of an atrial stimulating pulse by the atrial pulse generator and activates the ventricular sensing unit at the expiry of the blanking period. Due to the lower propagation speed of PVC depolarization waves and the multi-site sensing, a PVC depolarization wave initiated at a ventricular site during the blanking period can be detected by the IMD. | 09-27-2012 |
20120253419 | SYSTEMS AND METHODS FOR OPTIMIZING VENTRICULAR PACING BASED ON LEFT ATRIAL ELECTROMECHANICAL ACTIVATION DETECTED BY AN AV GROOVE ELECTRODE - Techniques are provided for use with an implantable cardiac stimulation device equipped with a multi-pole left ventricular (LV) lead having a proximal electrode implanted near an atrioventricular (AV) groove of the heart of the patient. A left atrial (LA) cardioelectrical event is sensed using the proximal electrode of the LV lead and a corresponding LA cardiomechanical event is also detected, either using an implantable sensor or an external detection system. The electromechanical activation delay between the LA cardioelectrical event and the corresponding LA cardiomechanical event is determined and then pacing delays are set based on the electromechanical activation delay for use in controlling pacing. The pacing delays can include, e.g., AV delays for use with biventricular cardiac resynchronization therapy (CRT) pacing. Other techniques described herein are directed to exploiting right atrial (RA) cardioelectrical events detected via an RA lead for the purposes of setting pacing delays. | 10-04-2012 |
20120277817 | PACING IN THE PRESENCE OF ELECTROMAGENTIC INTERFERENCE - This disclosure provides a pacing technique that reduces the effect of oversensing caused by noise on pacing therapy. The IMD delivers a pacing pulse subsequent to sensing an electrical signal on the lead when the sensed electrical signal coincides with an independently detected noise signal and the sensed electrical signal occurs during a period of time of an expected intrinsic cardiac signal. The IMD may, in some instances, trigger delivery of the pacing pulse during the escape interval instead of waiting for the escape interval to expire. Pacing in accordance with the techniques of this disclosure may allow for improved therapy during an MRI procedure by decreasing the risk associated with inappropriate pacing inhibition as well as decreasing the risk associated with pacing during the vulnerable period of the cardiac cycle. | 11-01-2012 |
20120303084 | SECURE AND EFFICACIOUS THERAPY DELIVERY FOR A PACING ENGINE - The above-described methods and apparatus are believed to be of particular benefit for patients suffering heart failure including cardiac dysfunction, chronic HF, and the like and all variants as described herein and including those known to those of skill in the art to which the invention is directed. It will understood that the present invention offers the possibility of monitoring and therapy of a wide variety of acute and chronic cardiac dysfunctions. The current invention provides systems and methods for delivering therapy for cardiac hemodynamic dysfunction via the innervated myocardial substrate receives one or more discrete pulses of electrical stimulation during the refractory period of said innervated myocardial substrate. | 11-29-2012 |
20120310296 | DETERMINATION OF CARDIAC RESYNCHRONIZATION THERAPY SETTINGS - CRT settings for an implantable medical device are determined by applying pacing pulses to heart chambers of a scheme of different combinations of interchamber delays. A respective width parameter value representing an R or P wave width is determined for each such delay combination based on an ECG representing signal and the width parameter values are employed to estimate a parametric model defining the width parameter as a function of interchamber delays. Candidate interchamber delays that minimize the width parameter are determined from the parametric model and employed to determine optimal CRT settings. The technique provides an efficient way of finding optimal CRT settings when multiple pacing sites are available in a heart chamber. | 12-06-2012 |
20120310297 | SYSTEM AND METHOD FOR AUTOMATED ADJUSTMENT OF CARDIAC RESYNCHRONIZATION THERAPY CONTROL PARAMETERS - A system and method for cardiac resynchronization therapy in which pacing control parameters are automatically adjusted by comparison of local electrograms acquired by a cardiac implantable electrical device with a model of cardiac electrical activity derived from surface-lead electrocardiograph measurements under baseline and paced conditions is provided. The adjusted pacing control parameters guarantee substantially maximum evidence of ventricular activation wavefront fusion while reducing the risk of compromising diastolic function. Atrioventricular intervals (AVIs] are measured and utilized to constrain the adjustment of pacing control parameters such that diastolic dysfunctions are not induced in the patient's heart. | 12-06-2012 |
20120330370 | Methods and Devices for Identifying Overdetection of Cardiac Signals - 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. | 12-27-2012 |
20130006321 | SYSTEM FOR MANAGING REFRACTORY PERIODS IN A CARDIAC RHYTHM MANAGEMENT DEVICE WITH BIVENTRICULAR SENSING - A method and system for managing refractory periods in a cardiac rhythm management device configured for biventricular or biatrial sensing. Refractory periods for each channel of the pacemaker are provided by interval timers that are triggered by sensed or paced events in order to prevent misinterpretation of sensing signals. | 01-03-2013 |
20130013018 | IDENTIFYING HEART FAILURE PATIENTS SUITABLE FOR RESYNCHRONIZATION THERAPY USING QRS COMPLEX WIDTH FROM AN INTRACARDIAC ELECTROGRAM - Methods and systems are disclosed for determining whether a patient is a responder to cardiac resynchronization therapy. The beginning and ending of the intrinsic ventricular depolarization are determined through signals measured from one or more electrodes implanted in the patient's heart. An interval between the beginning and ending of the intrinsic ventricular depolarization is computed and is compared to a threshold. The threshold may be determined empirically. The pacing parameters of a heart stimulation device, such as a pacemaker, may then be configured, for example, by setting the paced atrio-ventricular delay based on whether the patient responds positively to cardiac resynchronization therapy. | 01-10-2013 |
20130030489 | SAMPLING INTRINSIC AV CONDUCTION TIME - Methods and/or devices for sampling a patient's intrinsic AV conduction time during cardiac therapy that may, e.g., change the AV delays to values based on the AV delays themselves, previously-sampled intrinsic AV conduction times, and/or one or more other parameters directly related to AV delays to provide a time period during which to measure the patient's intrinsic AV conduction time. | 01-31-2013 |
20130035737 | SYSTEMS AND METHODS FOR DETERMINING PACING RELATED PARAMETERS - Pacing related timing is determined for an implantable medical device (IMD) by pacing at an RV pacing site, a first LV pacing site and a second LV pacing site in accordance with a first site, a second site and a third site pacing order, and further in accordance with a first inter-electrode pacing delay between pacing at the first site and pacing at the second site and a second inter-electrode pacing delay between pacing at the second site and pacing at the third site. At least one of a sensed event or a paced event is detected for at each of the second site and the third site. The first inter-electrode pacing delay and the second inter-electrode pacing delay are adjusted to avoid sensed events in favor of paced events at each of the second site and the third site. An atrio-ventricular delay may also be adjusted to avoid sensed events or lack of capture due to possible fusion at the first site, in favor of paced events at the first site. | 02-07-2013 |
20130035738 | METHODS AND SYSTEMS FOR DETERMINING PACING PARAMETERS BASED ON REPOLARIZATION INDEX - Methods and systems are provided for determining pacing parameters for an implantable medical device (IMD). The methods and systems provide electrodes in the right atrium (RA), right ventricle (RV) and left ventricle (LV). The methods and systems sense RV cardiac signals and LV cardiac signals at an RV electrode and an LV electrode, respectively, over multiple cardiac cycles, to collect global activation information. The methods and systems identify a T-wave in the LV cardiac signal. The methods and systems calculate a repolarization index based at least in part on a timing of the T-wave identified in the LV cardiac signal. The methods and systems set at least one pacing parameter based on the repolarization index, wherein the at least one pacing parameter that is set represents at least one of an AV delay, an inter-ventricular interval and an intra-ventricular interval. Optionally, the methods and systems may deliver an RV pacing stimulus at the RV electrode such that the LV cardiac signal sensed thereafter includes the RV pacing stimulus followed by a T-wave. The methods and systems determine a waveform metric such as at least one of a QT interval, T-wave duration, and T-wave amplitude, and utilize the waveform metric to determine as the repolarization index. | 02-07-2013 |
20130035739 | NERVE STIMULATION APPARATUS - Nerve stimulation is performed while suppressing occurrence of symptom caused by sinus node dysfunction or atrioventricular node dysfunction. Provided is a nerve stimulation apparatus including: a stimulation signal generator configured to output a stimulation signal to a nerve; a cardiac-event acquisition unit configured to acquire cardiac events; and a control unit configured to control the stimulation signal generator such that sinus node dysfunction or atrioventricular node dysfunction is determined to be occurring and energy of the stimulation signal is reduced when a time interval value between the adjacent cardiac events acquired by the cardiac-event acquisition unit exceeds a predetermined threshold. | 02-07-2013 |
20130079839 | APPARATUS AND METHOD TO OPTIMIZE PACING PARAMETERS - The present disclosure refers to a heart stimulator comprising a stimulation control unit, a stimulation unit, an impedance measurement unit and an impedance evaluation unit. The stimulation control unit is operatively connected to the stimulation unit to control timing of stimulation pulses by said stimulation unit. The impedance measurement unit is configured to determine an impedance signal reflecting intracardiac impedance. The impedance evaluation unit is operatively connected to the impedance measurement unit and to the stimulation control unit and is configured to evaluate the impedance signal so as to determine an isovolumic contraction time, an isovolumic relaxation time, an ejection time and a filling time from said impedance signal. The stimulation control unit is further configured to control timing of stimulation pulses depending on a performance index. | 03-28-2013 |
20130085539 | DYNAMIC CARDIAC RESYNCHRONIZATION THERAPY BY TRACKING INTRINSIC CONDUCTION - Systems and methods for pacing the heart using resynchronization pacing delays that achieve improvement of cardiac function are described. An early activation pacing interval is calculated based on an optimal AV delay and an atrial to early ventricular activation interval between an atrial event and early activation of a ventricular depolarization. The early activation pacing interval for the ventricle is calculated by subtracting the measured AV | 04-04-2013 |
20130090702 | BI-VENTRICULAR VENTRICULAR CAPTURE MANAGEMENT IN CARDIAC RESYNCHRONIZIATION THERAPY DELIVERY DEVICES - The present invention provides a technique for verifying pacing capture of a ventricular chamber, particularly to ensure desired delivery of a ventricular pacing regime (e.g., “CRT”). The invention also provides ventricular capture management by delivering a single ventricular pacing stimulus and checking inter-ventricular conduction during a temporal window to determine if the stimulus captured. If a loss-of-capture LOC) signal results from the capture management testing, then the applied pacing pulses are modified and the conduction test repeated. If LOC, an alert message can issue. Other aspects include: use of a trend of A-RV/LV and LV-RV timing intervals to monitor changes in the patient's heart conduction properties; bi-ventricular verification test and search—while still pacing BiV by detecting latent sense; single-V pacing threshold search, use of timing of sense in other V chamber to establish capture and LOC windows; (iv) use of a premature V pace rather than short AV interval if VV cannot be discriminated from AV; (v) option to run a threshold search only if the Bi-ventricular verification test fails. | 04-11-2013 |
20130110190 | METHOD TO ASSESS HEMODYNAMIC PERFORMANCE DURING CARDIAC RESYNCHRONIZATION THERAPY OPTIMIZATION USING ADMITTANCE WAVEFORMS AND DERIVATIVES | 05-02-2013 |
20130131750 | METHOD AND APPARATUS FOR ADAPTIVE CARDIAC RESYNCHRONIZATION THERAPY EMPLOYING A MULTIPOLAR LEFT VENTRICULAR LEAD - A medical device and associated method control the delivery of a cardiac pacing therapy by selecting first and second pacing sites along a first ventricle of a patient's heart and delivering the pacing therapy by pacing the first ventricle using the first pacing site during the periods of a first ventricular pacing mode and using the second pacing site during periods of a second ventricular pacing mode. In one embodiment, the device determines activation times at multiple sites along a ventricle in response to pacing pulses being delivered to the opposite ventricle. A first pacing site is selected in response to the activation time determination. The device delivers the pacing therapy by pacing the first ventricle using the first pacing site during periods of the first ventricular pacing mode. | 05-23-2013 |
20130131751 | APPARATUS AND METHOD FOR SELECTING A PREFERRED PACING VECTOR IN A CARDIAC RESYNCHRONIZATION DEVICE - A medical device and associated method control the delivery of a cardiac pacing therapy including selecting left ventricular pacing sites for delivering the therapy. The left ventricular pacing sites are selected by delivering pacing pulses to a patient's left ventricle at multiple pacing sites one at a time and determining right ventricular activation times in response to the pacing pulses being delivered at each of the pacing sites. A left ventricular pacing site is selected in response to the determined right ventricular activation times. | 05-23-2013 |
20130138172 | PACE COUNTER ISOLATION FOR CARDIAC RESYNCHRONIZATION PACING - A system and method for recording sensing and pacing events in a cardiac rhythm management device. The method may be particularly useful in assessment of pacing parameters for ventricular resynchronization therapy. | 05-30-2013 |
20130138173 | VAGAL STIMULATION DURING ATRIAL TACHYARRHYTHMIA TO FACILITATE CARDIAC RESYNCHRONIZATION THERAPY - 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. | 05-30-2013 |
20130165985 | MANAGING CROSS THERAPY DELIVERY IN A MULTIPLE THERAPY IMPLANTABLE DEVICE - An apparatus comprises a cardiac signal sensing circuit configured to sense an electrical cardiac signal from at least one of an atrium or ventricle of a heart of a subject, a therapy circuit configured to provide electrical pacing therapy and electrical neural stimulation therapy to the subject, and a control circuit. The control circuit is configured to initiate delivery of the electrical pacing therapy, initiate a blanking period in a time relationship to the delivery of electrical pacing therapy, and initiate delivery of the electrical neural stimulation therapy to the subject during the blanking period. At least one sense amplifier of the cardiac signal sensing circuit is disabled during the blanking period. | 06-27-2013 |
20130172954 | APPARATUSES AND METHODS USING THE ROLE OF VENTRICULAR ELECTRICAL DELAY TO PREDICT LEFT VENTRICULAR REMODELING WITH CARDIAC RESYNCHRONIZATION THERAPY - A system comprises a cardiac signal sensing circuit and a processor circuit. The cardiac signal sensing circuit is configured to sense a cardiac signal segment using a set of electrodes connectable to the cardiac signal sensing circuit. The processor circuit is communicatively coupled to the cardiac signal sensing circuit and includes a peak detector circuit. The peak detector circuit is configured to identify, in the cardiac signal segment, a fiducial indicative of ventricular activation that is local to at least one electrode of the first set of electrodes. The fiducial includes a first large positive or negative peak greater than a specified percentage of a maximum peak of the first cardiac signal segment. The processor circuit is configured to provide an indication of local ventricular activation to at least one of a user or process. | 07-04-2013 |
20130197599 | ADAPTIVE CARDIAC RESYNCHRONIZATION THERAPY - Cardiac resynchronization therapy (CRT) delivered to a heart of a patient may be adjusted based on detection of a surrogate indication of the intrinsic atrioventricular conduction of the heart. In some examples, the surrogate indication is determined to be a sense event of the first depolarizing ventricle of the heart within a predetermined period of time following the delivery of a fusion pacing stimulus to the later depolarizing ventricle. In some examples, the CRT is switched from a fusion pacing configuration to a biventricular pacing configuration if the surrogate indication is not detected, and the CRT is maintained in a fusion pacing configuration if the surrogate indication is detected. | 08-01-2013 |
20130289642 | PACING SEQUENCE OPTIMIZATION - An implantable medical device is connected to a multipolar LV lead and an implantable sensor. The sensor signal from the sensor is used to identify a time point of mitral valve closure for a cardiac cycle when a ventricular pulse generator generates pacing pulses that are applied to the electrodes of the multipolar LV lead according to a pacing sequence. A time interval processor determines the time interval from onset of LV activation to the time point of mitral valve closure. This procedure is repeated for multiple different pacing sequences of a sequence set. The pacing sequence that resulted in shortest time interval is then selected by a selector as the currently optimal pacing sequence for the patient. | 10-31-2013 |
20130310890 | SYSTEM AND METHOD FOR CARDIAC RESYNCHRONIZATION THERAPY CONTROL PARAMETER GENERATION USING VENTRICULAR ACTIVATION SIMULATION AND SURFACE ECG REGISTRATION - A system and method for cardiac resynchronization therapy (“CRT”] in which a model of baseline cardiac electrical activity, such as a model of global baseline cardiac electrical activity derived from various surface electrocardiograph (“ECG”) signals, is utilized to automatically adjust pacing control parameters of a cardiac implantable electrical device (“CIED”) are provided. The baseline model is modified with simulated pacing control parameters in an iterative fashion until ventricular electrical asynchrony is minimized. The simulated pacing control parameters resulting in the minimum ventricular electrical asynchrony are used to generate an updated model of ventricular activation, and this updated model is used to generate control parameters for the CIED using a QRS glyph morphological framework. | 11-21-2013 |
20130325081 | LEADLESS INTRA-CARDIAC MEDICAL DEVICE WITH DUAL CHAMBER SENSING THROUGH ELECTRICAL AND/OR MECHANICAL SENSING - A leadless intra-cardiac medical device senses cardiac activity from multiple chambers and applies cardiac stimulation to at least one cardiac chamber and/or generates a cardiac diagnostic indication. The leadless device may be implanted in a local cardiac chamber (e.g., the right ventricle) and detect near-field signals from that chamber as well as far-field signals from an adjacent chamber (e.g., the right atrium). | 12-05-2013 |
20130331904 | REMOTE PACE DETECTION IN AN IMPLANTABLE MEDICAL DEVICE - A system embodiment for stimulating a neural target comprises a neural stimulator, a pace detector, and a controller. The neural stimulator is electrically connected to at least one electrode, and is configured to deliver a neural stimulation signal through the at least one electrode to stimulate the neural target. The pace detector is configured to use at least one electrode to sense cardiac activity and distinguish paced cardiac activity in the sensed cardiac activity from non-paced cardiac activity in the sensed cardiac activity. The controller is configured to control a programmed neural stimulation therapy using the neural stimulator and using detected paced cardiac activity as an input for the neural stimulation therapy. | 12-12-2013 |
20140018877 | METHODS FOR PROMOTING INTRINSIC ACTIVATION IN SINGLE CHAMBER IMPLANTABLE CARDIAC PACING SYSTEMS - Cardiac pacing methods for an implantable single chamber pacing system, establish an offset rate for pacing at a predetermined decrement from either a baseline rate (i.e. dictated by a rate response sensor), or an intrinsic rate. Pacing maintains the offset rate until x of y successive events are paced events, at which time the offset rate is switched to the baseline rate for pacing over a predetermined period of time. Following the period, if an intrinsic event is not immediately detected, within the interval of the offset rate, the rate is switched back to baseline for pacing over an increased period of time. Some methods establish a preference rate, between the offset and baseline rates, wherein an additional criterion, for switching from the offset rate to the baseline rate, is established with respect to the preference rate. | 01-16-2014 |
20140018878 | LOCAL AND NON-LOCAL SENSING FOR CARDIAC PACING - Systems and methods for determining pacing timing intervals based on the temporal relationship between the timing of local and non-local cardiac signal features are described. A device includes a plurality of implantable electrodes electrically coupled to the heart and configured to sense local and non-local cardiac signals. Sense circuitry coupled to first and second electrode pairs senses a local cardiac signal via a first electrode pair and a non-local cardiac signal via a second electrode pair. Detection circuitry is used to detect a feature of the local signal associated with activation of a heart chamber and to detect a feature of the non-local signal associated with activation of the heart chamber. A control processor times delivery of one or more pacing pulses based on a temporal relationship between timing of the local signal feature and timing of the non-local signal feature. | 01-16-2014 |
20140031887 | IDENTIFYING HEART FAILURE PATIENTS SUITABLE FOR RESYNCHRONIZATION THERAPY USING QRS COMPLEX WIDTH FROM AN INTRACARDIAC ELECTROGRAM - Methods and systems are disclosed for determining whether a patient is a responder to cardiac resynchronization therapy. The beginning and ending of the intrinsic ventricular depolarization are determined through signals measured from one or more electrodes implanted in the patient's heart. An interval between the beginning and ending of the intrinsic ventricular depolarization is computed and is compared to a threshold. The threshold may be determined empirically. The pacing parameters of a heart stimulation device, such as a pacemaker, may then be configured, for example, by setting the paced atrio-ventricular delay based on whether the patient responds positively to cardiac resynchronization therapy. | 01-30-2014 |
20140046396 | METHODS AND DEVICES FOR ACCURATELY CLASSIFYING CARDIAC ACTIVITY - Methods, systems, and devices for signal analysis in an implanted cardiac monitoring and treatment device such as an implantable cardioverter defibrillator. In some examples, captured 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. Several examples emphasize the use of morphology analysis using correlation to static templates and/or inter-event correlation analysis. | 02-13-2014 |
20140058471 | MEASURING AUTONOMIC TONE USING ATRIOVENTRICULAR DELAY - An autonomic status indicator representative of a sympathetic/parasympathetic balance of a subject can use atrioventricular (AV) delays measured during recovery from (or in response to) elevated atrial pacing while the subject is at rest. | 02-27-2014 |
20140058472 | BIVENTRICULAR-TRIGGERED PACING IN THE CONTEXT OF MULTI-SITE LEFT VENTRICULAR PACING - Biventricular-triggered pacing is a pacing mode that can employ in cardiac resynchronization pacing at elevated heart rates. Described herein are methods and devices for implementing biventricular pacing in the context of multi-site left ventricular pacing. | 02-27-2014 |
20140222099 | SYSTEM AND METHOD FOR AUTOMATED ADJUSTMENT OF CARDIAC RESYNCHRONIZATION THERAPY CONTROL PARAMETERS - A system and method for cardiac resynchronization therapy (“CRT”) in which a model of baseline cardiac electrical activity, such as a model of global baseline cardiac electrical activity derived from various surface electrocardiograph (“ECG”) signals, is utilized to automatically adjust pacing control parameters of a cardiac implantable electrical device (“CIED”) are provided. The baseline model is compared to CRT response patterns using modified pacing control parameters in an iterative fashion, based on a patient-specific response pattern phenotype determination, until ventricular electrical asynchrony is minimized. The pacing control parameters resulting in the minimum ventricular electrical asynchrony are used to generate final control parameters for CRT. | 08-07-2014 |
20140309707 | Implantable Pacemakers Control and Optimization via Fractional Calculus Approaches - Method and system for non-linear modeling of physiological behavior, such as R-R intervals, in implantable devices, such as a rate responsive pacemakers, comprising a comprehensive modeling and optimization methodology based on fractional calculus and constrained finite horizon optimal control theory that allows for allows for fine-grain optimization of pacemaker response to heart rate variations; and the theoretical basis on which a hardware implementation of the fractional optimal controller that can respond to changes in the heart rate dynamics. Present invention describes a fractal approach to pacemaker control based on the constrained finite horizon optimal control problem. This is achieved by modeling the heart rate dynamics via fractional differential equations. Also, by using calculus of variations, the invention describes how the constrained finite horizon optimal control problem can be reduced to solving a linear system of equations. Finally, the invention describes the theoretical basis on which a hardware implementation become possible. | 10-16-2014 |
20140324116 | ACTIVE IMPLANTABLE MEDICAL DEVICE FOR THE TREATMENT OF HEART FAILURE WITH VAGUS NERVE STIMULATION IN SYNCHRONY WITH CARDIAC ACTIVITY - A medical device includes a VNS pulse burst generator for stimulation of the vagus nerve, and a controller for analyzing the cardiac rhythm. It further includes a sequencer that uses an estimator to calculate during a given cycle an estimate of the temporal position of the R wave of the next cycle. The controller is configured to define the moment of application of the VNS pulse burst as an instant corresponding to the estimate minus a predetermined advance delay. VNS therapy is thus delivered in a non-vulnerable period, near the end of the period of natural ventricular escape. | 10-30-2014 |
20140330330 | AUTOMATIC SELECTION OF STIMULATION CHAMBER FOR VENTRICULARRESYNCHRONIZATION THERAPY - A method and apparatus for selection of one or more ventricular chambers to stimulate for ventricular resynchronization therapy. Intrinsic intracardia electrograms that include QRS complexes, are recorded from a left and right ventricle. A timing relationship between the intrinsic intracardia electrograms recorded from the left and right ventricle is then determined. In one embodiment, the timing relationship is determined using a delay between a left ventricular and a right ventricular sensed intrinsic ventricular depolarizations and a duration interval of one or more QRS complexes. In one embodiment, the duration of QRS complexes is determined from either intracardiac electrograms or from surface ECG recordings. One or more ventricular chambers in which to provide pacing pulses are then selected based on the timing relationship between intrinsic intracardia electrograms recorded from the right and left ventricle, and the duration of one or more QRS complexes. | 11-06-2014 |
20150134024 | ADAPTIVE CARDIAC RESYNCHRONIZATION THERAPY - Cardiac resynchronization therapy (CRT) delivered to a heart of a patient may be adjusted based on detection of a surrogate indication of the intrinsic atrioventricular conduction of the heart. In some examples, the surrogate indication is determined to be a sense event of the first depolarizing ventricle of the heart within a predetermined period of time following the delivery of a fusion pacing stimulus to the later depolarizing ventricle. In some examples, the CRT is switched from a fusion pacing configuration to a biventricular pacing configuration if the surrogate indication is not detected, and the CRT is maintained in a fusion pacing configuration if the surrogate indication is detected. | 05-14-2015 |
20150142072 | SYSTEMS AND METHODS FOR DETERMINING OPTIMAL INTERVENTRICULAR PACING DELAYS BASED ON ELECTROMECHANICAL DELAYS - Techniques are provided for use with implantable medical devices such as pacemakers for optimizing interventricular (VV) pacing delays for use with cardiac resynchronization therapy (CRT). In one example, ventricular electrical depolarization events are detected within a patient in whom the device is implanted. The onset of isovolumic ventricular mechanical contraction is also detected based on cardiomechanical signals detected by the device, such as cardiogenic impedance (Z) signals, S1 heart sounds or left atrial pressure (LAP) signals. Then, an electromechanical time delay (T_QtoVC) between ventricular electrical depolarization and the onset of isovolumic ventricular mechanical contraction is determined. VV pacing delays are set to minimize the time delay to the onset of isovolumic ventricular mechanical contraction. Various techniques for identifying the onset of isovolumic ventricular contraction based on Z, S1 or LAP or other cardiomechanical signals are described. In some examples, CRT nonresponders are specifically identified and/or heart failure progression is tracked. | 05-21-2015 |