A heart monitoring system comprising:
- an implantable medical device;
- a service center;
- a central data base;
- a user interface;
- said implantable medical device comprising
- a stimulation pulse generator configured to generate electric stimulation pulses and configured to connect to at least a ventricular stimulation electrode configured to deliver said electric stimulation pulses to at least a ventricle of a heart;
- a ventricular sensing stage configured to connect to an electrode configured to pick up electric potentials inside said at least said ventricle of said heart, said sensing stage configured to sense an excitation or a contraction of ventricular myocardium;
- an activity sensor;
- an impedance determination unit comprising
- a constant current source or a constant voltage source having current feed terminals that are configured to connect to electrodes for intracorporeal placement wherein said constant current source or said constant voltage source is configured to generate sub-threshold measuring current pulses having a constant current strength or a constant voltage, respectively, that cause a current to be fed through a body via intracorporeally placed electrodes;
- a measuring unit configured to measure a voltage corresponding to said current fed through said body by said constant current source or a current strength of said current fed through said body by said constant voltage source, respectively;
- an impedance value determination unit that is connected to said constant current source or said constant voltage source wherein said measuring unit is configured to determine an impedance value for each of said sub-threshold measuring current pulses;
- said impedance determination unit configured to perform an intrathoracic impedance measurement via a first and a second electrode combination wherein said second electrode combination is different from said first electrode combination;
- a battery;
- a control unit that is connected to said battery, said stimulation pulse generator, said ventricular sensing stage, said activity sensor and said impedance determination unit and that is configured to collect data representing values of:
- DC thoracic impedance from said first electrode combination,
- DC thoracic impedance from said second electrode combination,
- cardiac output,
- heart rate at a resting state of a patient,
- heart rate during exercise of said patient,
- activity level of said patient,
- ventricular extra systoles or VES per time unit,
- breathing rate,
- tidal volume;
- an implant transceiver unit configured to communicate with said service center;
- said service center comprising another data communication interface configured to allow at least an indirect data communication with said implantable medical device wherein said another data communication interface is connected to said central data base and to said user interface;
- wherein said control unit is configured to initiate transmission of said collected data to said service center;
- said service center further comprising a data evaluation module connected to said data base wherein said data evaluation module is configured to evaluate data stored in said data base including data trending of stored data, wherein said data evaluation module is further configured to generate a decompensation indicator signal if a change in said DC thoracic impedance from said first electrode combination and said DC thoracic impedance from said second electrode combination show a preset increase and activity level shows a preset decrease and said breathing rate shows a second preset increase;
- and,
- said user interface and said data evaluation module are further configured to allow a physician to set for each data, trend trigger criteria that signifies detection of decompensation and wherein said data evaluation module is further configured to generate said decompensation indicator signal whenever a combination of trigger criteria are met by trended data.