St. Jude Medical Ab

Malin Hollmark

Stefan Hjelm

Tomas Svensson

Kjell Noren

Anders Bjorling

Sven-Erik Hedberg

Karin Järverud

Anders Björling

Kjell Norén

Michael Broome

Andreas Karlsson

A patient-specific hemodyanmic status model is determined from impedance data collected during periods of normal and abnormal hemodynamic status by deriving parameter values of a set of multiple impedance-derivable parameters from impedance signals collected during periods of normal hemodynamic status and in connection with periods of abnormal hemodynamic status. The parameter values are employed to estimate coefficients of a linear parametric status model. These coefficients can then be used together with parameter values determined from impedance signals determined during status assessment periods in order to determine a current hemdoynamic status of the patient.

Hemodynamic status assessment

An implantable medical device, is designed to collect a signal representative of the electric activity of the heart and determine a cardiogenic impedance signal for at least a portion of the heart. An R-wave detector of the IMD detects the timing of an R-wave during a cardiac cycle based on the signal representative of the electric activity. A minimum detector detects the timing of a cardiogenic impedance minimum in the cardiogenic impedance signal and within a systolic time window of the cardiac cycle. A detected arrhythmia is then classified by the IMD based on the timing of the R-wave detected by the R-wave detector and the timing of the cardiogenic impedance minimum detected by the minimum detector.

Arrhythmia classification

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.

Pacing sequence optimization

An implantable medical device () is configured for generating a cardiogenic impedance signal representative of the cardiogenic impedance of at least a portion of a heart () of a subject () during at least a portion of cardiac cycle. A moment processor () calculates a moment parameter value based on the cardiogenic impedance signal. The moment parameter is representative of a weighted sum of impedance amplitudes within a time window centered at defined time instance within the cardiac cycle. The weights of the impedance amplitudes are further dependent on the length in time between the defined time instance and the point of time of the associated impedance amplitude. The moment parameter is of high diagnostic value and is employed by an arrhythmia classifier () in order to classify a detected arrhythmia of the heart (), such as discriminate between hemodynamically stable or unstable arrhythmias and/or supraventricular or ventricular tachycardia.

Implantable medical device and method comprising means for detecting and classifying an arrhythmia

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Solna, Sweden

Malin Hollmark