Abstract: An implantable bi-ventricular heart stimulating device (10) has a control circuit with first and second sensing circuits for respectively sensing in the two ventricles and first and second stimulation circuits for respectively stimulating the two ventricles. The control circuit determines whether a signal, sensed by said second sensing circuit, occurs essentially simultaneously with a signal sensed by the first sensing circuit. Furthermore, the control circuit determines whether a further signal is sensed by said second sensing circuit within a predetermined time interval which follows after the signal sensed by the second sensing circuit but within the same time cycle as that signal. If this occurs, the control circuit determines whether the sensed signals represent actual cardiac events, or are likely the result of far field detection.

Abstract: In a monitor for monitoring diastolic relaxation of a ventricle of a heart, an impedance signal is measured in a ventricle of the heart and the occurrence of a notch in the impedance signal coincident with the entry of blood into the monitored ventricle is detected by forming a time derivative of the impedance signal and generating a loop by plotting impedance values of the impedance signals with respect to related time derivative values to form a loop for each cardiac cycle of the heart, and comparing the generated loop to a loop template representing a normal loop for the subject, to identify deviations in the loop from normal deviations in timing and shape of the notch.

Abstract: A multi-chamber pacing system has a pulse generator for successively delivering pacing pulses to chambers of a patient's heart, and IEGM signal detectors, having blanking intervals following the delivery of pacing pulses, including sensing circuits for sensing IEGM-signals from each of the heart chambers. Each of said sensed IEGM signals has a generally known morphology. A signal-reconstructing unit reconstructs the IEGM signal from one of the heart chambers in the blanking interval following delivery of a pacing pulse to another heart chamber.

Abstract: An implantable bi-ventricular heart stimulating device (10) has a control circuit with first and second sensing circuits for respectively sensing in the two ventricles and first and second stimulation circuits for respectively stimulating the two ventricles. The control circuit determines whether a signal, sensed by said second sensing circuit, occurs essentially simultaneously with a signal sensed by the first sensing circuit. Furthermore, the control circuit determines whether a further signal is sensed by said second sensing circuit within a predetermined time interval which follows after the signal sensed by the second sensing circuit but within the same time cycle as that signal. If this occurs, the control circuit determines whether the sensed signals represent actual cardiac events, or are likely the result of far field detection.

Abstract: An implantable bi-ventricular heart stimulating device and system operate, within a time cycle, to deliver pacing pulses with both a first and a second pacing circuit with a first time delay between these pacing pulses. The device employs a criterion with which a signal typical for a premature ventricular contraction is detected. The device also operates with a second time delay and/or with a third time delay, and, if a predefined pacing rule is fulfilled, to deliver a pacing pulse with the second time delay or said third time delay. The risk for arrhythmia in connection with a PVC is reduced.

Abstract: A multi-chamber pacing system has a pulse generator for successively delivering pacing pulses to chambers of a patient's heart. Evoked response detectors having blanking intervals following the delivery of pacing pulses include sensing elements for sensing IEGM-signals from each of the heart chambers and an integrating unit that integrates the IEGM-signal within evoked response detection time windows after delivery of pacing pulses for detecting evoked response. The evoked response detection time window for a heart chamber contain at least one blanking interval resulting from delivery of a pacing pulse to another chamber and each of the sensed IEGM signals having a generally known morphology. An integral reconstructing unit reconstructs the time integral of the IEGM signal from one of the heart chambers in the blanking interval following delivery of a pacing pulse to another heart chamber.

Abstract: A multi-chamber pacing system has a pulse generator for successively delivering pacing pulses to chambers of a patient's heart, and IEGM signal detectors, having blanking intervals following the delivery of pacing pulses, including sensing circuits for sensing IEGM-signals from each of the heart chambers. Each of said sensed IEGM signals has a generally known morphology. A signal-reconstructing unit reconstructs the IEGM signal from one of the heart chambers in the blanking interval following delivery of a pacing pulse to another heart chamber.

Abstract: An implantable bi-ventricular heart stimulating device and system, suitable for treating congestive heart failure, have a control circuit with first and second pacing circuits and first and second sensing circuits. The device operates with time cycles corresponding to normal heart cycles. The control circuit determines: (a) whether a signal typical of an evoked response to a pacing pulse delivered by the first pacing circuit is sensed within a first time interval and (b) whether a signal typical for an R-wave transferred from the second ventricle, or from some other part of the heart, to the first ventricle is detected within a first time window. The operation of the device depends on whether the conditions (a) and (b) are fulfilled.

Abstract: A monitor for early detection of an ischemic heart disease of a patient has an impedance measurement unit including an electrode arrangement for measuring an intracardiac impedance and generating a corresponding impedance signal, a notch detector connected to the impedance measurement unit for detecting the occurrence of a notch in the impedance signal coincident with the entry of blood into the ventricle, and a pattern recognition unit which compares the measured post-notch impedance curve with a stored predetermined reference impedance curve template to detect an ischemic heart disease from the result of the comparison.

Abstract: In a monitor for monitoring diastolic relaxation of a ventricle of a heart, an impedance signal is measured in a ventricle of the heart and the occurrence of a notch in the impedance signal coincident with the entry of blood into the monitored ventricle is detected by forming a time derivative of the impedance signal and generating a loop by plotting impedance values of the impedance signals with respect to related time derivative values to form a loop for each cardiac cycle of the heart, and comparing the generated loop to a loop template representing a normal loop for the subject, to identify deviations in the loop from normal deviations in timing and shape of the notch.

Abstract: A pacemaker has control circuits contained in an enclosure and a lead containing an electrical conductor connected to an electrode for delivering electrical stimulation pulses to a heart. The stretching of a wall in the ventricle, corresponding to adequate filling of the ventricle in the heart, is determined in order to identify a time of emitting the stimulation pulses. This stretching is measured indirectly by measurement of pressure in the ventricle using a pressure sensor disposed near the lead in the ventricle. The signal from the sensor is supplied via the lead to circuitry in the enclosure, wherein the signal is amplified and is supplied to an edge detector, which detects an increasing or positive edge of the signal.

Abstract: A device for identifying abnormal conditions in a heart retrograde conduction and tachyarrhythmias in particular, includes a differentiating circuit electrically connected to a heart to be monitored in order to differentiate ECG signals from the heart. The differentiated signal is plotted against the ECG signal. The radius (distance from a point on the resulting curve from the origin of the plot axes) in the resulting curve is calculated in a calculator unit. The radius obtained is then compared with a threshold value in a comparator and a sequence for the progression of the radius in relation to the threshold value is obtained and compared with previously obtained sequences stored in a sequence analyzer.