Abstract: An implantable medical device comprises a connector connectable to an implantable oxygen sensor configured to generate a sensor signal representative of oxygen concentration in coronary sinus blood in a subject's heart. An ischemia detector is connected to the connector and configured to detect an ischemic event in the heart if the sensor signal indicates a temporary decrease in oxygen concentration in the coronary sinus blood below a normal level followed by a temporary increase in oxygen concentration in the coronary sinus blood above the normal level.

Abstract: An analyte measuring system has an implantable medical device having a signal source arranged for generating a current signal and electrodes for applying the current signal to a surrounding tissue in a subject body. The device measures a resulting voltage signal with the electrodes and calculates an impedance signal therefrom. The system comprises a signal processor arranged for generating an estimate of a concentration of an analyte in the tissue based on a spectrum analysis of the determined impedance signal.

Abstract: Systems and methods for optimizing the stimulation of a heart of a patient are disclosed herein. The method comprises delivering pacing therapy to the patient according to a pacing therapy setting schedule, using specific pacing intervals via specific electrode configurations. Further, sinus rate values are recorded over at least one cardiac cycle at each pacing therapy setting and it is determined whether a sinus rate value satisfies predetermined measurement conditions, wherein sinus rate values are used for trending the sinus rate over time if the measurement conditions are satisfied. The accepted sinus rate values, i.e. values that satisfy the measurement conditions, are trended over time, wherein each trended sinus rate value is created based on recordings from at least one cardiac cycle. A preferred pacing therapy setting is determined to be the pacing therapy setting that provides a lowest sinus rate.

Abstract: Implantable heart stimulator connectable to an electrode arrangement has a pulse generator adapted to deliver stimulation pulses to a heart of a subject; an impedance measurement unit adapted monitor at least one heart chamber of the heart of the subject to measure the impedance in the at least one monitored heart chamber for generating an impedance signal corresponding to the measured impedance. The impedance signal is applied to a processor where the signal is processed, according to specified criteria, and a fractionation index value is determined represented by the curve length of the impedance signal during a predetermined measurement period. The fractionation index value is a measure of different degrees of mechanical dyssynchrony of the heart.

Abstract: In a method and implantable medical device for ventricular tachyarrhythmia detection and classification, upon detection of a ventricular tachyarrhythmia based on an electrocardiogram signal, cardiogenic impedance data representative of ventricular volume dynamics are collected and used for classifying the detected tachyarrhythmia as stable or unstable. In the latter case but typically not in the former case, defibrillation shocks or other forms of therapy are applied to combat the unstable ventricular tachyarrhythmia.

Abstract: An implantable cardiac device has a heart stimulator for electrically stimulating the heart of a patient, detector that measures a physiologic parameter that is affected by the status of a cardiovascular disease associated with sympathetic activation, a signal processor that determines at least one of a low frequency, LF, and a very low frequency, VLF, Mayer wave component in the measured parameter, and analyzer that automatically analyzes the determined Mayer wave component in relation to a predetermined reference value to determine the status of the cardiovascular disease. The detector is a cardio-mechanical parameter detector that measures, as said physiologic parameter, a mechanical change in at least one of the four chambers of the heart. In a corresponding method for monitoring the status of a cardiovascular disease associated with sympathetic activation of a patient having an implantable electric heart stimulator a physiologic parameter affected by the cardiac disease is measured.

Abstract: An implantable medical device, IMD, (100) is connectable to at least one ventricular lead (210) having a ventricular basal electrode (214) and a ventricular apical electrode (212). The IMD (100) comprises a pulse generator (120) for generating pacing pulses applied to a heart (10) through the ventricular lead (210). The operation of this pulse generator (120) is controlled by a controller (130) that is configured to control the pulse generator to first deliver a pacing pulse to the ventricular basal electrode (214) to stimulate the basal portion of the ventricle (12, 14) before a pacing pulse is delivered to the apical portion of the ventricle (12, 14) by the ventricular apical electrode (212). This pulse sequence achieves a biologically more correct cardiac stimulation and a contraction pattern that reduces the risk for valvular regurgitation.

Abstract: In a method and an apparatus for creating hemodynamic sensor signal templates using an implantable medical device connectable to a patient heart activity of the patient is sensed in order to identify a paste or sensed sequence of events of a heart cycle. Hemodynamic sensor signals for consecutive heart cycles are sensed and the sensed hemodynamic sensor signals for consecutive heart cycles are stored. The sensed sensor signals are classified dependent on at least one predetermined heart event sequence condition. A template may be created using the classified sensor signals.

Abstract: In an implantable heart stimulator and a method for operation thereof, stimulation pulses are delivered to a heart. The amplitude of the delivered stimulation pulses can be selectively set. For setting the amplitude, threshold searches are performed at selected time intervals. Each threshold search determines a threshold value required for achieving capture. The amplitudes of the respective stimulation pulses are set to a value that exceeds the determined threshold value by a safety margin. The safety margin is selected as a function of the selected time intervals.

Abstract: The present invention generally relates to an implantable medical device and method for detecting and monitoring cardiac status of a patient using simultaneous multisite measurements of the intracardiac impedance and in particular to ischemia detection using the simultaneous multisite measurements. The device comprises an impedance measuring unit being connectable to a plurality of electrode configurations including a current generating device adapted to generate a current and apply the current between two electrodes of a current injecting electrode configuration of the electrode configurations and a voltage sensing device including a plurality of voltage sensing circuits arranged in parallel.

Abstract: In a method and medical device for detecting an ischemic episode and to determine a location of ischemia in a heart of a patient, an impedance measuring circuit measures the impedances in the tissue between electrodes of at least one electrode configuration according to a predetermined measurement scheme and an ischemia detector evaluates the measured impedance values using at least one reference impedance image of the heart to detect changes in the measured impedances that are consistent with an ischemia and to determine a location of the ischemia to at least one region of the image.

Abstract: An implantable heart monitoring system includes a housing configured for implantation in a subject, at least one sensor member implanted relative to the heart of the subject to detect an electrical signal related to cardiac activity of the heart, a control circuit in the housing, and a memory accessible by the control circuit.

Abstract: A method for detecting a condition of a heart of a patient using an implantable medical device, including the steps of sensing acoustic signals indicative of heart sounds of the heart of the patient; extracting signals corresponding to a first heart sound (S1) and a second heart sound (S2) from sensed signals; calculating an energy value corresponding to a signal corresponding to the first heart sound (S1) and an energy value corresponding to the second heart sound (S2); calculating a relation between the energy value corresponding to the first heart sound and the energy value corresponding to the second heart sound for successive cardiac cycles; and using at least one relation to detect the condition or a change of the condition. A medical device for determining the posture of a patient and a computer readable medium encoded with instructions are used to perform the inventive method.

Abstract: In a biventricular heart stimulator and a method for controlling such a biventricular heart stimulator, successive stimulation pulses are delivered to the ventricles of a heart such that stimulation pulses in a single heartbeat cycle are respectively first delivered to the first ventricle and then to the second ventricle. Capture or loss of capture in response to stimulation pulses delivered to one ventricle is detected. As a result of a detected loss of capture, preventative measures are taken for preventing loss of capture in the other ventricle.

Abstract: An implantable medical device applies an electric signal over two electrodes and measures the resulting electric signal over a candidate pair of neighboring electrodes on a lead for a first heart ventricle or over a candidate electrode of the lead and a case electrode. An impedance signal is determined for each candidate pair or electrode based on the applied signal and the measured resulting signal. A time difference between start of contraction in a second ventricle and the timing of local myocardial contraction as identified from the impedance signal at the site of the candidate pair or electrode is determined for each candidate pair or electrode. An optimal pacing electrode is selected to correspond to one of the electrodes of the candidate pair having the largest time difference or the candidate electrode having largest time difference.

Abstract: A method for operating an implantable medical device to control a stimulation therapy includes the steps of: sensing an acoustic energy; producing acoustic signals indicative of heart sounds of the heart of the patient over predetermined periods of a cardiac cycle during successive cardiac cycles; extracting a signal corresponding to a first heart sound (S1) from a measured acoustic signal; calculating an energy value corresponding to the extracted signal; storing the energy value corresponding to the first heart sound; and initiating an optimization procedure, the optimization procedure comprising the steps of: iteratively controlling a delivery of the pacing pulses based on successive energy values corresponding to successive first heart sound signals and determining an optimal PV interval or AV interval with respect to the energy values. A medical device and a computer readable medium to implement the method.

Abstract: In an implantable medical device and a method for monitoring ventricular synchronicity of a heart, impedance signals are measured that reflect septal wall movements and impedance amplitude peaks in the impedance signal are detected. A synchronicity index indicating a degree of synchronicity is determined based on detected impedance peaks, with at least two impedance peaks detected within a predetermined time window including a cardiac cycle or a part of a cardiac cycle indicating an increased dyssynchronicity in the ventricular contractions.

Abstract: An implantable cardiac stimulation device has an atrial detector that detects atrial events of a patient's heart, and a memory in which sequences of IEGM signals are stored, having a predetermined length, and an analyzing unit that analyzes the sequences to determine if the stored sequences contain atrial events having a lower amplitude than the current sensitivity setting of the atrial detector. A control unit is connected to the atrial detector to adjust the sensitivity setting thereof to a threshold that is determined based on the aforementioned analysis of the IEGM signals.

Abstract: In an apparatus and method for detecting incipient heart failure of a patient. Impedance signals reflecting volume changes of the right ventricle and/or the right atrium of a heart of the patient are obtained. The impedance signals are processed to determine a first impedance parameter substantially reflecting a volume of the right ventricle, and a heart failure status is determined based on the first impedance parameter, wherein a decreasing first impedance parameter is determined to be an indication of a deterioration of the heart failure status.

Abstract: In an implantable biventricular heart stimulating device, and a biventricular heart stimulating method, wherein operation takes place normally with a time VV between a pacing pulse delivered, or inhibited, by a first ventricular pacing circuit and a pacing pulse delivered, or inhibited, by a second ventricular pacing circuit, and wherein a time VVcts is determined that is to be used instead of VV during a capture threshold search.