Abstract: An implantable medical device uses a method for dynamically managing physiological signal monitoring. A physiological signal is sensed for detecting physiological events in response a first threshold. A determination is made whether a second threshold has been met in response to detecting physiological events. If the second threshold has been met, detailed monitoring of the physiological events is enabled.

Abstract: There is provided an implantable cardiac pacing system or other cardiac monitoring system having an enhanced capability to classify intracardiac signals through a combination of DSP techniques and software algorithms. The implantable device has one or more DSP channels corresponding to different signals which are being monitored. Each DSP channel most preferably amplifies the incoming signal, converts the signal from analog to digital form, digitally filters the converted signals to provide a filtered signal, operates on the filtered signal to provide a slope signal, determines from the filtered and slope signals when an intracardiac event has been detected, signal processes the filtered and slope signals for a predetermined analysis interval after threshold crossing, and generates a plurality of wave parameters corresponding to the signal.

Abstract: A system and method for characterizing the atrial wall of the heart is provided. The characterization of the atrial wall can be used for a variety of diagnostic and therapeutic purposes. For example, it can be used to detect precursors to various types of hear disease, such as atrial fibrillation. In one embodiment, the system and method is used to determine a likelihood of fibrosis in the atrial wall. Furthermore, the system and method can detect changes in atrial wall fibrosis that can indicate a continuing degradation in the atrial wall health and an increasing likelihood of atrial fibrillation. In another embodiment, the system and method is used to determine if electrical instability exists in the atrial wall.

Abstract: A method of pacing opposing chambers of a heart with a pacing system is provided. The pacing system comprises a first bipolar medical electrical lead having at least one first electrode configured for positioning in a first opposing chamber of the heart, a second bipolar medical electrical lead having at least one second electrode configured for positioning in a second opposing chamber of the heart, an implantable pulse generator operably connected to the first and second bipolar medical electrical leads. The implantable pulse generator further comprises a hermetically sealed housing capable of serving as a can electrode. The method designates a primary electrode configuration by selecting a cathode and an anode from either the first electrode, second electrode, or the can. Selection of the cathode is based on a comparison of thresholds measured in each chamber. Systems, programs and devices using the method are also provided.

Abstract: An implantable medical device (IMD) system as disclosed herein includes a telemetry transceiver device that can receive wireless IMD data from an IMD, along with wireless physiological sensor data from an external physiological sensor device. Wireless communication between the IMD and the telemetry transceiver device is performed in accordance with a first wireless data communication protocol, and wireless communication between the external physiological sensor device and the telemetry transceiver device is performed in accordance with a second wireless data communication protocol. The telemetry transceiver device can function as a hub that communicates patient data to a centralized remote computing architecture. The remote computing architecture may include software applications for processing the received patient data.

Abstract: An implantable medical device uses a method for dynamically managing physiological signal monitoring. A physiological signal is sensed for detecting physiological events in response a first threshold. A determination is made whether a second threshold has been met in response to detecting physiological events. If the second threshold has been met, detailed monitoring of the physiological events is enabled.

Abstract: A system and method for characterizing the atrial wall of the heart is provided. The characterization of the atrial wall can be used for a variety of diagnostic and therapeutic purposes. For example, it can be used to detect precursors to various types of hear disease, such as atrial fibrillation. In one embodiment, the system and method is used to determine a likelihood of fibrosis in the atrial wall. Furthermore, the system and method can detect changes in atrial wall fibrosis that can indicate a continuing degradation in the atrial wall health and an increasing likelihood of atrial fibrillation. In another embodiment, the system and method is used to determine if electrical instability exists in the atrial wall.

Abstract: A system and method for use in an implanted cardiac pacing device, whereby an optimal AV delay is determined at or near lower rate (pacing) limit (LRL) by determining measuring the variance, or instability, of the QT interval for a set of intervals. In one embodiment, asynchronous “LRL pacing” with a first programmed AV delay determines a measure of QT variance. The difference between the maximum QT and the minimum QT is expressed as QT difference (QTD). For each programmed AV delay the QT variance is again measured and the optimal AV delay produces minimum QTD. In another embodiment, AV delay is modulated around base values for a time. The difference between QT for the modulated AV and for the base AV (dQT) is measured at each base value, and the optimal AV delay corresponds to the smallest dQT.

Abstract: A method of pacing opposing chambers of a heart with a pacing system is provided. The pacing system comprises a first unipolar medical electrical lead having at least one first electrode configured for positioning in a first opposing chamber of the heart, a second unipolar medical electrical lead having at least one second electrode configured for positioning in a second opposing chamber of the heart, an implantable pulse generator operably connected to the first and second unipolar medical electrical leads. The implantable pulse generator further comprises an hermetically sealed housing capable of serving as a can electrode, and means for switching electrode configurations between the first electrode and the can electrode, between the second electrode and the can electrode, between the first electrode and the second electrode and between the second electrode and the first electrode. A primary electrode configuration is determined.

Abstract: A method of pacing opposing chambers of a heart with a pacing system is provided. The pacing system comprises a first unipolar medical electrical lead having at least one first electrode configured for positioning in a first opposing chamber of the heart, a second unipolar medical electrical lead having at least one second electrode configured for positioning in a second opposing chamber of the heart, an implantable pulse generator operably connected to the first and second unipolar medical electrical leads. The implantable pulse generator further comprises an hermetically sealed housing capable of serving as a can electrode, and means for switching electrode configurations between the first electrode and the can electrode, between the second electrode and the can electrode, between the first electrode and the second electrode and between the second electrode and the first electrode. A primary electrode configuration is determined.

Abstract: A system and method for use in an implanted cardiac pacing device, whereby an optimal AV delay is determined at or near lower rate (pacing) limit (LRL) by determining measuring the variance, or instability, of the QT interval for a set of intervals. In one embodiment, asynchronous “LRL pacing” with a first programmed AV delay determines a measure of QT variance. The difference between the maximum QT and the minimum QT is expressed as QT difference (QTD). For each programmed AV delay the QT variance is again measured and the optimal AV delay produces minimum QTD. In another embodiment, AV delay is modulated around base values for a time. The difference between QT for the modulated AV and for the base AV (dQT) is measured at each base value, and the optimal AV delay corresponds to the smallest dQT.

Abstract: Method and device for determining capture status of a heart chamber that receives a pulse from an implantable pulse generator (IPG). Signal processing can be used to improve the reliability of capture detection by transforming the sensed response signal into a set of morphological characteristics. Analysis of selected morphological characteristics serves to distinguish signals indicative of capture from signals indicative of loss of capture.

Abstract: An implantable medical device includes a sensor and a T-wave analyzer. The sensor is implantable within the body of a patient to sense electrical cardiac activity and provide an indication of T-wave alternans within the heart of the patient. The T-wave analyzer is responsive to the sensor, and evaluates cardiac risk based on comparison of the indication of T-wave alternans to a predetermined criterion. The T-wave analyzer may form part of a microprocessor, a digital signal processor, or combination of both. The device may include a pacing generator that applies increased rate pacing stimuli to the heart to facilitate sensing of the T-wave alternans by the sensor. The device also may incorporate a memory that stores the T-wave alternans indication provided by the sensor, e.g., over a number of heartbeats. In addition, the device may be equipped to provide an alert to the patient or a physician in the event the processor generates the indication of cardiac risk.

Abstract: In general, the invention is directed to techniques for determining capture status of a heart chamber that receives a pulse from an implantable pulse generator (IPG). Digital signal processing (DSP) can be used to improve the reliability of capture detection by transforming the sensed response signal into a set of morphological characteristics. Analysis of selected morphological characteristics serves to distinguish signals indicative of capture from signals indicative of loss of capture.

Abstract: An implantable medical device (IMD) selectively switches to a more hemodynamically beneficial pacing mode upon detection of ventricular dysynchrony and/or reduced hemodynamic function during delivery of pacing pulses according to a ventricular rate stabilization algorithm. For example, in some embodiments of the invention, an IMD switches from right ventricular pacing according to a ventricular rate stabilization algorithm, to biventricular pacing according to the algorithm. The biventricular pacing can be provided according to a cardiac resynchronization therapy mode, and can involve use of an intraventricular delay between delivery of pacing pulses to the respective ventricles to improve hemodynamic functioning of a heart. The IMD monitors an electrogram signal to detect ventricular dysynchrony and/or decreased hemodynamic performance of the ventricles. The IMD can detect ventricular dysynchrony based on elongated QRS complex widths.

Abstract: A method of determining kidney failure in a patient using an implantable medical device is described. In one embodiment, a first magnitude of a first polarization signal is measured. An additional magnitude of an additional polarization signal is measured after a first interval. A deflection differential between the first magnitude and the additional magnitude is determined and kidney failure in the patient is determined when the deflection differential is greater than an established threshold.

Abstract: A method of diagnosing pulmonary congestion is provided. At least one decrease in a trans-thoracic impedance value from a baseline trans-thoracic impedance value is sensed. At least one increase in a heart rate value from a baseline heart rate value is also sensed. Pulmonary congestion is diagnosed if the decrease in the trans-thoracic impedance value corresponding to the increase in the heart rate does not increase after a predetermined interval. Systems and programs incorporating the method are also provided.

Abstract: A method of pacing opposing chambers of a heart with a pacing system is provided. The pacing system comprises a first unipolar medical electrical lead having at least one first electrode configured for positioning in a first opposing chamber of the heart, a second unipolar medical electrical lead having at least one second electrode configured for positioning in a second opposing chamber of the heart, an implantable pulse generator operably connected to the first and second unipolar medical electrical leads. The implantable pulse generator further comprises an hermetically sealed housing capable of serving as a can electrode, and means for switching electrode configurations between the first electrode and the can electrode, between the second electrode and the can electrode, between the first electrode and the second electrode and between the second electrode and the first electrode. A primary electrode configuration is determined.

Abstract: A method of determining kidney failure in a patient using an implantable medical device is described. In one embodiment, a first magnitude of a first polarization signal is measured. An additional magnitude of an additional polarization signal is measured after a first interval. A deflection differential between the first magnitude and the additional magnitude is determined and kidney failure in the patient is determined when the deflection differential is greater than an established threshold.

Abstract: A method of diagnosing pulmonary congestion is provided. At least one decrease in a trans-thoracic impedance value from a baseline trans-thoracic impedance value is sensed. At least one increase in a heart rate value from a baseline heart rate value is also sensed. Pulmonary congestion is diagnosed if the decrease in the trans-thoracic impedance value corresponding to the increase in the heart rate does not increase after a predetermined interval. Systems and programs incorporating the method are also provided.