Patent application number | Description | Published |
20080275520 | Automatic modulation of pacing timing intervals using beat to beat measures - Methods and systems to modulate timing intervals for pacing therapy are described. For each cardiac cycle, one or both of an atrioventricular (A-V) timing interval and an atrial (A-A) timing interval are modulated to oppose beat-to-beat ventricular (V-V) timing variability. Pacing therapy is delivered using the modulated timing intervals. | 11-06-2008 |
20080306568 | 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. | 12-11-2008 |
20090048637 | 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. | 02-19-2009 |
20090054944 | Modulation of AV delay to control ventricular interval variability - System and methods provide pacing therapy that modulates the atrioventricular (AV) delay to control ventricular interval variability. A base AV delay is determined as a function of heart rate. For each cardiac cycle, the base AV delay is modulated to reduce beat-to-beat variability of successive ventricular beats. The modulated AV delay compensates for variability of successive atrial beats. For example, modulation of the base AV delay may involve varying the AV delay inversely with a change in atrial interval. | 02-26-2009 |
20090054945 | Method, apparatus, and system to optimize cardiac preload based on measured pulmonary artery pressure - Optimizing cardiac preload based on measured pulmonary artery pressure involves varying, for each repetition of an acute burst protocol, a parameter of pacing applied to a patient's heart during the acute burst protocol. Pulmonary artery pressure is measured during the repetitions of the acute burst protocol. An optimum ventricular preload is determined based on the measured pulmonary artery pressure. Pacing therapy is provided using a value of the parameter that is selected based on the determination of optimum ventricular preload. | 02-26-2009 |
20090076557 | Closed Loop Cardiac Resynchronization Therapy Using Cardiac Activation Sequence Information - Cardiac monitoring and/or stimulation methods and systems that provide one or more of monitoring, diagnosing, defibrillation, and pacing. Cardiac signal separation is employed to detect, monitor, track and/or trend closed-loop cardiac resynchronization therapy using cardiac activation sequence information. Devices and methods involve sensing a plurality of composite cardiac signals using a plurality of electrodes, the electrodes configured for implantation in a patient. A source separation is performed using the sensed plurality of composite cardiac signals, producing one or more cardiac signal vectors associated with all or a portion of one or more cardiac activation sequences. A cardiac resynchronization therapy is adjusted using one or both of the one or more cardiac signal vectors and the signals associated with the one or more cardiac signal vectors. In further embodiments, the cardiac resynchronization therapy may be initiated, terminated, or one or more parameters of the resynchronization therapy may be altered. | 03-19-2009 |
20090112276 | DETERMINATION OF STIMULATION DELAY BETWEEN VENTRICULAR SITES - An earlier intrinsic activation and a later intrinsic activation of a right ventricle and a left ventricle are determined. This information is used for computing a biventricular pacing interval as a function of an interval from a pacing energy delivered to a ventricle corresponding to the later intrinsic activation and a depolarization sensed in a ventricle having earlier intrinsic activation, the depolarization evoked in response to the pacing energy. | 04-30-2009 |
20090118783 | Monitoring Right Ventricular Hemodynamic Function During Pacing Optimization - Method and systems related to monitoring right ventricular function during pacing by a cardiac rhythm management device are described. One or more pacing parameters are selected to provide cardiac resynchronization therapy. For example, the one or more pacing parameters may be selected to provide an optimal or improved therapy. The heart is paced using the selected pacing parameters. While pacing with the selected parameters, pressure is sensed via a pressure sensor disposed the pulmonary artery. The sensed pressure is analyzed to determine right ventricular function achieved during the pacing using the selected pacing parameters. A signal, such as an alert signal or control signal, is generated based on the right ventricular function achieved during the pacing. | 05-07-2009 |
20090198299 | METHOD AND APPARATUS FOR OPTIMIZING VENTRICULAR SYNCHRONY DURING DDD RESYNCHRONIZATION THERAPY USING ADJUSTABLE ATRIO-VENTRICULAR DELAYS - A pacing system for providing optimal hemodynamic cardiac function for parameters such as ventricular synchrony or contractility (peak left ventricle pressure change during systole or LV+dp/dt), or stroke volume (aortic pulse pressure) using system for calculating atrio-ventricular delays for optimal timing of a ventricular pacing pulse. The system providing an option for near optimal pacing of multiple hemodynamic parameters. The system deriving the proper timing using electrical or mechanical events having a predictable relationship with an optimal ventricular pacing timing signal. | 08-06-2009 |
20090240159 | SENSING CARDIAC CONTRACTILE FUNCTION - Systems and methods for detecting and measuring cardiac contractile function of a heart using an acceleration sensor unit inserted within the heart, such as within a vein of the cardiac wall are disclosed. The systems and methods involve detecting the occurrence of electrical events within the patient's heart by inserting and positioning an implantable lead having an electrode near a cardiac wall as well as detecting mechanical events within the patient's heart by then inserting and positioning a cardiac motion sensor unit through the inner lumen of the implantable lead. Furthermore, the systems and methods do not require dedicated leads and may be used with preexisting implantable leads. | 09-24-2009 |
20090248104 | AUTOMATIC SELECTION OF STIMULATION CHAMBER FOR VENTRICULAR RESYNCHRONIZATION THERAPY - A device and method for programming an implantable pulse generator. In one embodiment, commands are entered designating implantable pulse generator programming variables into programmer memory. At least some of the commands are transformed into an executable macro. The macro is stored in the programmer memory. The macro is executed to transmit the programming variables to the implantable pulse generator. | 10-01-2009 |
20090264949 | ELECTROGRAM MORPHOLOGY-BASED CRT OPTIMIZATION - A method and system for determining an optimum atrioventricular delay (AVD) interval and/or ventriculo-ventricular delay (VVD) intervals for delivering ventricular resynchronization pacing in an atrial tracking or atrial sequential pacing mode. Evoked response electrograms recorded at different AVD and VVD intervals are used to determine the extent of paced and intrinsic activation. | 10-22-2009 |
20090312815 | Systems and Methods for Improving Heart Rate Kinetics in Heart Failure Patients - Adaptive rate pacing for improving heart rate kinetics in heart failure patients involves determining onset and sustaining of patient activity. The patient's heart rate response to the sustained activity is evaluated during a time window defined between onset of the activity and a steady-state exercise level. If the patient's heart rate response to the sustained activity is determined to be slow, a pacing therapy is delivered at a rate greater than the patient's intrinsic heart rate based on a profile of the patient's heart rate response to varying workloads. If determined not to be slow, the pacing therapy is withheld. Monitoring-only configurations provide for acquisition and organization of physiological data for heart failure patients. These data can be acquired on a per-patient basis and used to assess the HF status of the patient. | 12-17-2009 |
20100010557 | SELECTIVE RESYNCHRONIZATION THERAPY OPTIMIZATION BASED ON USER PREFERENCE - A method and system for calculating an atrio-ventricular delay interval based upon an inter-atrial delay exhibited by a patient's heart. The aforementioned atrio-ventricular delay interval may optimize the stroke volume exhibited by a patient's heart. The aforementioned atrio-ventricular delay interval may be blended with another atrio-ventricular delay interval that may optimize another performance characteristic, such as left ventricular contractility. Such blending may include finding an arithmetic mean, geometric mean, or weighted mean of two or more proposed atrio-ventricular delay intervals. | 01-14-2010 |
20100023078 | Cardiac resynchronization therapy parameter optimization - Systems and methods involve determination of CRT parameters using a number of CRT optimization processes. Each CRT optimization process attempts to return recommended parameters. The CRT parameters are determined based on the recommended parameters returned by one or more of the CRT optimization processes. The CRT optimization processes may be sequentially implemented and the CRT parameters may be determined based on the recommended parameters returned by a first CRT optimization process to return recommended parameters. The CRT parameters may be determined based on a combination of the recommended parameters returned. The CRT optimization processes implemented may be selected from available CRT optimization processes based on patient conditions. | 01-28-2010 |
20100056884 | THORACIC OR INTRACARDIAC IMPEDANCE DETECTION WITH AUTOMATIC VECTOR SELECTION - This document discusses, among other things, a cardiac function management device or other implantable medical device that includes a test mode and a diagnostic mode. During a test mode, the device cycles through various electrode configurations for collecting thoracic impedance data. At least one figure of merit is calculated from the impedance data for each such electrode configuration. In one example, only non-arrhythmic beats are used for computing the figure of merit. A particular electrode configuration is automatically selected using the figure of merit. During a diagnostic mode, the device collects impedance data using the selected electrode configuration. In one example, the figure of merit includes a ratio of a cardiac stroke amplitude and a respiration amplitude. Other examples of the figure of merit are also described. | 03-04-2010 |
20100069988 | 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. | 03-18-2010 |
20100131026 | METHOD AND APPARATUS FOR USING HEART RATE VARIABILITY AS A SAFETY CHECK IN ELECTRICAL THERAPIES - A cardiac rhythm management system modulates the delivery of pacing and/or autonomic neurostimulation pulses based on heart rate variability (HRV). An HRV parameter being a measure of the HRV is produced to indicate a patient's cardiac condition, based on which the delivery of pacing and/or autonomic neurostimulation pulses is started, stopped, adjusted, or optimized. In one embodiment, the HRV parameter is used as a safety check to stop an electrical therapy when it is believed to be potentially harmful to continue the therapy. | 05-27-2010 |
20100137932 | METHOD AND APPARATUS FOR OPTIMIZING ELECTRICAL STIMULATION PARAMETERS USING HEART RATE VARIABILITY - A cardiac rhythm management system modulates the delivery of pacing and/or autonomic neurostimulation pulses based on heart rate variability (HRV). An HRV parameter being a measure of the HRV is produced to indicate a patient's cardiac condition, based on which the delivery of pacing and/or autonomic neurostimulation pulses is started, stopped, adjusted, or optimized. In one embodiment, the HRV parameter is used to evaluate a plurality of parameter values for selecting an approximately optimal parameter value. | 06-03-2010 |
20100298729 | Cardiac Activation Sequence Monitoring for Ischemia Detection - Cardiac monitoring and/or stimulation methods and systems that provide one or more of monitoring, diagnosing, defibrillation, and pacing. Cardiac signal separation is employed to detect, monitor, track and/or trend ischemia using cardiac activation sequence information. Ischemia detection may involve sensing composite cardiac signals using implantable electrodes, and performing a signal separation that produces one or more cardiac activation signal vectors associated with one or more cardiac activation sequences. A change in the signal vector may be detected using subsequent separations. The change may be an elevation or depression of the ST segment of a cardiac cycle or other change indicative of myocardial ischemia, myocardial infarction, or other pathological change. The change may be used to predict, quantify, and/or qualify an event such as an arrhythmia, a myocardial infarction, or other pathologic change. Information associated with the vectors may be stored and used to track the vectors. | 11-25-2010 |
20110054557 | DYNAMIC DEVICE THERAPY CONTROL FOR TREATING POST MYOCARDIAL INFARCTION PATIENTS - A cardiac rhythm management system includes an implantable device executing a dynamic pacing algorithm after an myocardial infarction (MI) event. The dynamic pacing algorithm dynamically adjusts one or more pacing parameters based on a person's gross physical activity level. Examples of the one or more pacing parameters include atrioventricular pacing delays and pacing channels/sites. The dynamic pacing algorithm provides for improved hemodynamic performance when a person's metabolic need is high, and post MI remodeling control when the person's metabolic need is low. | 03-03-2011 |
20110071588 | CARDIAC PACING USING ADJUSTABLE ATRIO-VENTRICULAR DELAYS - A pacing system for providing optimal hemodynamic cardiac function for parameters such as contractility (peak left ventricle pressure change during systole or LV+dp/dt), or stroke volume (aortic pulse pressure) using system for calculating atrio-ventricular delays for optimal timing of a ventricular pacing pulse. The system providing an option for near optimal pacing of multiple hemodynamic parameters. The system deriving the proper timing using electrical or mechanical events having a predictable relationship with an optimal ventricular pacing timing signal. | 03-24-2011 |
20110092836 | METHOD AND APPARATUS FOR DETERMINING THE CORONARY SINUS VEIN BRANCH ACCESSED BY A CORONARY SINUS LEAD - Systems and methods for determining the coronary sinus vein branch location of a left ventricle electrode are disclosed. The systems and methods involve detecting the occurrence of electrical events within the patient's heart including sensing one or more of the electrical events with the electrode and then analyzing the electrical events to determine the electrode's position. The determination of electrode position may be used to automatically adjust operating parameters of a VRT device. Furthermore, the determination of electrode position may be made in real-time during installation of the electrode and a visual indication of the electrode position may be provided on a display screen. | 04-21-2011 |
20110093031 | CARDIAC RESYNCHRONIZATION SYSTEM EMPLOYING MECHANICAL MEASUREMENT OF CARDIAC WALLS - Methods and devices are disclosed for employing mechanical measurements to synchronize contractions of ventricular wall locations. Accelerometers that may be placed within electrode leads are positioned at ventricular wall locations, such as the left ventricle free wall, right ventricle free wall, and the anterior wall/septum wall. The accelerometers produce signals in response to the motion of the ventricular wall locations. A processor may then compare the signals to determine a difference in the synchronization of the ventricular wall location contractions. The difference in synchronization can be determined in various ways such as computing a phase difference and/or amplitude difference between the accelerometer signals. One or more stimulation pulses may be provided per cardiac cycle to resynchronize the contractions as measured by the accelerometers to thereby constantly and automatically optimize the cardiac resynchronization therapy. | 04-21-2011 |
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 |
20110130801 | Pacing Output Configuration Selection for Cardiac Resynchronization Therapy Patients - Cardiac therapy systems include multiple electrodes respectively positionable at multiple left ventricular electrode sites. A pulse generator is coupled to the electrodes and configured to deliver a cardiac resynchronization therapy (CRT). A processor is configured to measure, for each left ventricular electrode site, a timing interval between first and second cardiac signal features associated with left ventricular depolarization. The timing interval is associated with a degree of responsiveness of each left ventricular electrode site to CRT. The processor is configured to determine a pacing output configuration that provides improved patient responsiveness to CRT based on the timing interval measurements and to select at least one left ventricular electrode site from the plurality of left ventricular electrode sites based on the timing interval measurements. The processor may be configured to monitor for a change in hemodynamic status of the patient based on a change in the timing interval. | 06-02-2011 |
20110137192 | Arrhythmia Discrimination using ECG's Sensed from Multiple Implanted Electrodes - Cardiac monitoring and/or stimulation methods and systems provide for monitoring, diagnosing, defibrillation and pacing therapies, or a combination of these capabilities, including cardiac systems incorporating or cooperating with neuro-stimulating devices, drug pumps, or other therapies. Embodiments of the present invention relate generally to implantable medical devices employing automated cardiac activation sequence monitoring and/or tracking for arrhythmia discrimination. Embodiments of the invention are directed to devices and methods involving sensing a plurality of composite cardiac signals using a plurality of implantable electrodes. A source separation is performed using the sensed plurality of composite cardiac signals and the separation produces one or more cardiac signal vectors associated with one or more cardiac activation sequences that is indicative of ischemia. A change of the one or more cardiac signal vectors is detected using the one or more cardiac signal vectors. Cardiac arrhythmias are discriminated using the one or more cardiac signal vectors. | 06-09-2011 |
20110144511 | Cardiac Activation Sequence Monitoring and Tracking - Cardiac monitoring and/or stimulation methods and systems provide monitoring, diagnosis, and defibrillation and/or pacing therapies. A signal processor receives a plurality of composite signals associated with a plurality of sources, performs a source separation, and produces one or more cardiac signal vectors associated with all or a portion of one or more cardiac activation sequences based on the source separation. A method of signal separation involves detecting a change in a characteristic of the cardiac signal vector relative to a baseline. One or more vectors and/or activation sequences may be selected, and information associated with the vectors and/or activation sequences may be stored and tracked. | 06-16-2011 |
20110160789 | Modulation of AV Delay to Control Ventricular Interval Variability - System and methods provide pacing therapy that modulates the atrioventricular (AV) delay to control ventricular interval variability. A base AV delay is determined as a function of heart rate. For each cardiac cycle, the base AV delay is modulated to reduce beat-to-beat variability of successive ventricular beats. The modulated AV delay compensates for variability of successive atrial beats. For example, modulation of the base AV delay may involve varying the AV delay inversely with a change in atrial interval. | 06-30-2011 |
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 |
20110301471 | THORACIC OR INTRACARDIAC IMPEDANCE DETECTION WITH AUTOMATIC VECTOR SELECTION - Vector selection is automatically achieved via a thoracic or intracardiac impedance signal collected in a cardiac function management device or other implantable medical device that includes a test mode and a diagnostic mode. During a test mode, the device cycles through various electrode configurations for collecting thoracic impedance data. At least one figure of merit is calculated from the impedance data for each such electrode configuration. In one example, only non-arrhythmic beats are used for computing the figure of merit. A particular electrode configuration is automatically selected using the figure of merit. During a diagnostic mode, the device collects impedance data using the selected electrode configuration. In one example, the figure of merit includes a ratio of a cardiac stroke amplitude and a respiration amplitude. Other examples of the figure of merit are also described. | 12-08-2011 |
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 |
20120130220 | GUIDEWIRE AND SIGNAL ANALYZER FOR PACING SITE OPTIMIZATION - Cardiac lead implantation systems, devices, and methods for lead implantation are disclosed. An illustrative cardiac lead implantation system comprises a mapping guidewire including one or more electrodes configured for sensing cardiac electrical activity, a signal analyzer including an analysis module configured for analyzing an electrocardiogram signal sensed by the mapping guidewire, and a user interface configured for monitoring one or more hemodynamic parameters within the body. The sensed electrical activity signal can be used by the analysis module to compute a timing interval associated with ventricular depolarization. | 05-24-2012 |
20120130440 | AUTOMATIC DETERMINATION OF CHRONOTROPIC INCOMPETENCE USING ATRIAL PACING AT REST - An apparatus comprises an implantable cardiac signal sensing circuit that provides an electrical cardiac signal representative of cardiac activity of a subject, an implantable therapy circuit that delivers electrical pacing stimulation energy to a heart of a subject, and a controller circuit. The controller circuit includes a chronotropic incompetence detection circuit that initiates pacing of an atrium of the subject at a rate higher than a device-indicated rate or a sensed intrinsic rate, monitor the AV interval, initiates an increase in the pacing rate while continuing the monitoring of the AV interval, calculates a change in AV intervals between a highest paced rate used in the monitoring and a lowest paced rate used in the monitoring, and indicates that the AV intervals are evidence of chronotropic incompetence when the calculated change in the AV intervals exceeds a specified threshold AV interval change value. | 05-24-2012 |
20120130443 | Automatic Adaptation of A-V Delay and HR for Heart Failure using Beat to Beat Measures - Methods and systems to modulate timing intervals for pacing therapy are described. For each cardiac cycle, one or both of an atrioventricular (A-V) timing interval and an atrial (A-A) timing interval are modulated to oppose beat-to-beat ventricular (V-V) timing variability. Pacing therapy is delivered using the modulated timing intervals. | 05-24-2012 |
20120158083 | LEFT VENTRICULAR PACING PROTECTION IN THE CONTEXT OF MULTI-SITE LEFT VENTRICULAR PACING - In a pacing mode where the left ventricle is paced upon expiration of an escape interval that is reset by a right ventricular sense, there is the risk that the left ventricular pace may be delivered in the so-called vulnerable period that occurs after a depolarization and trigger an arrhythmia. To reduce this risk, a left ventricular protective period (LVPP) may be provided. Methods and devices for implementing an LVPP in the context of multi-site left ventricular pacing are described. | 06-21-2012 |
20120158084 | LEFT VENTRICLE-ONLY AND RIGHT VENTRICULAR SAFETY PACING IN THE CONTEXT OF MULTI-SITE LEFT VENTRICULAR PACING - One way in which cardiac resynchronization therapy may be delivered is to only deliver paces to the left ventricle. If left ventricular pacing is inhibited during a cardiac cycle, it may be desirable to deliver a right ventricular safety pace to prevent asystole. Methods and devices for implementing right ventricular safety pacing in the context of multi-site left ventricular-only pacing are described. | 06-21-2012 |
20120158085 | 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. | 06-21-2012 |
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 |
20120226328 | CARDIAC RESYNCHRONIZATION THERAPY PARAMETER OPTIMIZATION - Systems and methods involve determination of CRT parameters using a number of CRT optimization processes. Each CRT optimization process attempts to return recommended parameters. The CRT parameters are determined based on the recommended parameters returned by one or more of the CRT optimization processes. The CRT optimization processes may be sequentially implemented and the CRT parameters may be determined based on the recommended parameters returned by a first CRT optimization process to return recommended parameters. The CRT parameters may be determined based on a combination of the recommended parameters returned. The CRT optimization processes implemented may be selected from available CRT optimization processes based on patient conditions. | 09-06-2012 |
20120238889 | METHOD AND APPARATUS FOR DETERMING THE CORONARY SINUS VEIN BRANCH ACCESSED BY A CORONARY SINUS LEAD - Systems and methods for determining the coronary sinus vein branch location of a left ventricle electrode are disclosed. The systems and methods involve detecting the occurrence of electrical events within the patient's heart including sensing one or more of the electrical events with the electrode and then analyzing the electrical events to determine the electrode's position. The determination of electrode position may be used to automatically adjust operating parameters of a VRT device. Furthermore, the determination of electrode position may be made in real-time during installation of the electrode and a visual indication of the electrode position may be provided on a display screen. | 09-20-2012 |
20120277607 | METHOD AND APPARATUS FOR IDENTIFICATION OF ISCHEMIC/INFARCTED REGIONS AND THERAPY OPTIMIZATION - A method and apparatus is described for detecting and localizing areas of myocardial infarction or ischemia. By pacing sites in proximity to the infarcted or ischemic region with appropriately timed pacing pulses, the region is pre-excited in a manner that lessens the mechanical stress to which it is subjected, thus reducing the metabolic demand of the region and the stimulus for remodeling. | 11-01-2012 |
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 |
20130123874 | MONITORING RIGHT VENTRICULAR HEMODYNAMIC FUNCTION DURING PACING OPTIMIZATION - Method and systems related to monitoring right ventricular function during pacing by a cardiac rhythm management device are described. One or more pacing parameters are selected to provide cardiac resynchronization therapy. For example, the one or more pacing parameters may be selected to provide an optimal or improved therapy. The heart is paced using the selected pacing parameters. While pacing with the selected parameters, pressure is sensed via a pressure sensor disposed the pulmonary artery. The sensed pressure is analyzed to determine right ventricular function achieved during the pacing using the selected pacing parameters. A signal, such as an alert signal or control signal, is generated based on the right ventricular function achieved during the pacing. | 05-16-2013 |
20130158621 | ECTOPIC-TRIGGERED PARA-HIS STIMULATION - Ectopic cardiac activity can be detected, such as in the absence of a diagnosed tachyarrhythmia episode. In response to the detected ectopic activity, electrostimulation can be provided to a para-Hisian region, such as to activate natural cardiac contraction mechanisms or to interrupt re-entrant cardiac activity. Subsequent ectopic cardiac activity can be detected, and subsequent electrostimulation can be provided to the para-Hisian region, such as according to one or more adjustable electrostimulation parameters. | 06-20-2013 |
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 |
20130190636 | OPTIMIZATION OF LV AND RV LEAD PLACEMENT BASED ON ELECTRICAL DELAYS - A system comprises a cardiac signal sensing and a processing circuit. The cardiac signal sensing circuit senses a first cardiac signal segment that includes a QRS complex and a second cardiac signal segment that includes a fiducial indicative of local ventricular activation. The processor circuit includes a site activation timer circuit configured to determine a time duration between a fiducial of the QRS complex of the first cardiac signal segment and the fiducial of the second cardiac signal segment. The processor circuit is configured to generate, using the determined time duration, an indication of optimality of placement of one or more electrodes for delivering therapy and provide the indication to at least one of a user or process. | 07-25-2013 |
20130253350 | METHOD AND APPARATUS FOR RECOGNIZING SENSED CARDIAC EVENTS USING DIFFERENT ELECTRODE CONFIGURATIONS - A system senses a cardiac signal for diagnostic and/or therapy control purposes using a first set of electrodes and switches to a different second set of electrodes for recognizing cardiac events in the cardiac signal. In various embodiments, the cardiac signal sensed using the second set of electrodes is compared to the cardiac signal sensed using the first set of electrodes, and the cardiac events in the cardiac signal are each recognized using an outcome of the comparison. | 09-26-2013 |
20130261685 | COORDINATED HIS-BUNDLE PACING AND HIGH ENERGY THERAPY - A cardiac arrhythmia can be identified, such as a tachycardia or fibrillation episode (atrial or ventricular). In responses to the detected arrhythmia, a coordinated electrostimulation therapy can be provided using at least one of a defibrillation shock therapy, a pre-shock conditioning therapy, or a post-shock conditioning therapy. The pre-shock or post-shock conditioning therapies can include electrostimulation therapies provided to the natural electrical conduction system of the heart between the atrioventricular node and the Purkinje fibers, inclusive, such as at or near a His bundle of a heart. In an example, a defibrillation threshold can be reduced by providing a pre-shock conditioning electrostimulation therapy to the natural electrical conduction system of the heart between the atrioventricular node and the Purkinje fibers, inclusive, such as at or near a His bundle. | 10-03-2013 |
20130274821 | AUTOMATIC MODULATION OF PACING TIMING INTERVALS USING BEAT TO BEAT MEASURES - Methods and systems to modulate timing intervals for pacing therapy are described. For each cardiac cycle, one or both of an atrioventricular (A-V) timing interval and an atrial (A-A) timing interval are modulated to oppose beat-to-beat ventricular (V-V) timing variability. Pacing therapy is delivered using the modulated timing intervals. | 10-17-2013 |
20130281867 | THORACIC OR INTRACARDIAC IMPEDANCE DETECTION WITH AUTOMATIC VECTOR SELECTION - Vector selection is automatically achieved via a thoracic or intracardiac impedance signal collected in a cardiac function management device or other implantable medical device that includes a test mode and a diagnostic mode. During a test mode, the device cycles through various electrode configurations for collecting thoracic impedance data. At least one figure of merit is calculated from the impedance data for each such electrode configuration. In one example, only non-arrhythmic beats are used for computing the figure of merit. A particular electrode configuration is automatically selected using the figure of merit. During a diagnostic mode, the device collects impedance data using the selected electrode configuration. In one example, the figure of merit includes a ratio of a cardiac stroke amplitude and a respiration amplitude. Other examples of the figure of merit are also described. | 10-24-2013 |
20130282074 | 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. | 10-24-2013 |
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 |
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 |
20140067002 | SELECTION OF PACING SITES TO ENHANCE CARDIAC PERFORMANCE - Systems and methods for selection of electrodes and related pacing configuration parameters used to pace a heart chamber are described. A change in the hemodynamic state of a patient is detected. Responsive to the detected change, a distribution of an electrical, mechanical, or electromechanical parameter related to contractile function of a heart chamber with respect to locations of multiple electrodes disposed within the heart chamber is determined. A pacing output configuration, including one or more electrodes of the multiple electrodes, is selected and the heart chamber is paced using the selected pacing output configuration. | 03-06-2014 |
20140100625 | LEFT VENTRICULAR PACING PROTECTION IN THE CONTEXT OF MULTI-SITE LEFT VENTRICULAR PACING - In a pacing mode where the left ventricle is paced upon expiration of an escape interval that is reset by a right ventricular sense, there is the risk that the left ventricular pace may be delivered in the so-called vulnerable period that occurs after a depolarization and trigger an arrhythmia. To reduce this risk, a left ventricular protective period (LVPP) may be provided. Methods and devices for implementing an LVPP in the context of multi-site left ventricular pacing are described. | 04-10-2014 |
20140142649 | METHODS AND APPARATUS FOR PREDICTING ACUTE RESPONSE TO CARDIAC RESYNCRONIZATION THERAPY AT A GIVEN STIMULATION SITE - Response to cardiac resynchronization therapy is predicted for a given stimulation site so that an atrioventricular delay of an implantable device administering cardiac resynchronization therapy may be set to a proper amount. The first deflection of ventricular depolarization is measured, such as through a surface electrocardiogram or through an intracardiac electrogram measured by a lead positioned in the heart at the stimulation site. The maximum deflection of the ventricular depolarization is then measured by the lead positioned at the stimulation site. The interval of time between the first deflection and the maximum deflection of the ventricular depolarization is compared to a threshold to determine whether the stimulation site is a responder site. If the interval is larger than the threshold, then the site is a responder and the atrioventricular delay of the implantable device may be set to less than the intrinsic atrioventricular delay of the patient. Otherwise, the atrioventricular may be set to approximately equal the intrinsic atrioventricular delay. | 05-22-2014 |
20140172035 | METHOD AND APPARATUS FOR RIGHT VENTRICULAR RESYNCHRONIZATION - An apparatus comprises a cardiac signal sensing circuit and a first implantable electrode pair. At least one electrode of the first implantable electrode pair is configured for placement at a location in a right branch of a His bundle of the subject. The apparatus can include a therapy circuit and a control circuit. The control circuit can include an AH delay calculation circuit configured to calculate an optimal paced AH delay interval. The pacing stimulation location is distal to a location of RV conduction block in a right branch of the His bundle. The control circuit initiates delivery of an electrical stimulation pulse to the stimulation location in the His bundle according to the calculated paced AH delay interval and in response to an intrinsic depolarization event sensed in an atrium of the subject. | 06-19-2014 |
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 |