Monitoring mechanical heart properties

摘要

In a method and system for monitoring mechanical properties of a heart in a subject, multiple cardiogenic impedance values reflective of the impedance of the heart in connection with a transition from inhalation to exhalation in the subject are determined. Correspondingly, multiple cardiogenic impedance values reflective of the impedance of the heart in connection with a transition from exhalation to inhalation are determined. The impedance values are collectively processed to form a trend parameter. The value determination and processing is performed over several respiratory cycles spaced apart in time to form a plurality of trend parameters over time. The mechanical properties of the heart are monitored by processing these different trend parameters. The data collection and optionally at least a part of the data processing is performed by an implantable medical device.

主权项

1. A method of monitoring mechanical properties of a heart in a subject, comprising the steps of:
a) determining a first set of multiple cardiogenic impedance values reflective of the impedance of said heart during a defined period of a heart cycle occurring in connection with a transition from inhalation to exhalation in said subject; b) determining a second set of multiple cardiogenic impedance values reflective of the impedance of said heart during said defined period of a heart cycle occurring in connection with a transition from exhalation to inhalation in said subject; c) collectively processing with a data processor said multiple cardiogenic impedance values of said first set as a function of said second set to determine a relationship between the first and second set and analyzing the relationship between the first and second sets to form a trend parameter representative of respiratory effect on said cardiogenic impedance values; d) repeating said determining steps a), b) and processing step c) to form a plurality of trend parameters over time; and e) monitoring said mechanical properties of said heart by processing said plurality of trend parameters.