Devices and method for determining and monitoring a cardiac status of a patient by using PLVDT or PLVST parameters

An implantable medical device for determining a cardiac status of a patient, said medical device being connectable to at least one medical lead for contact with tissue of a heart of said patient, said device comprising:

• a sensor arrangement adapted to sense cardiac signals related to mechanical activity of said heart and to produce an output signal related to the mechanical activity;
• an activity level sensor arrangement adapted to sense an activity level of said patient;
• a cardiac event identifying module adapted to identify predetermined cardiac events in the cardiac signals and to determine a systolic time interval and a diastolic time interval of a cardiac cycle using said identified cardiac events;
• a calculation module adapted to calculate a percentage of left ventricular diastolic time (PLVDT) for a cardiac cycle corresponding to a relation between a diastolic time interval and a cardiac cycle time interval using said determined systolic and diastolic time intervals or a percentage of left ventricular systolic time (PLVST) for a cardiac cycle corresponding to a relation between a systolic interval time interval and a cardiac cycle time interval using said determined systolic and diastolic time intervals, wherein said calculation module is adapted to determine a rate of change of said PLVDT (or PLVST) and said activity level;
• and
• a cardiac status determining module adapted to synchronize the activity level with said calculated PLVDT (or PLVST) over time and to determine a cardiac status based on said calculated PLVDT (or PLVST) and on said activity level and on a rate of change of said PLVDT (or PLVST) and on a rate of change of said activity level;
• wherein PLVDT=LVDT/(LVDT+LVST) and PLVST=LVST/(LVDT+LVST);
• wherein said sensor arrangement includes a heart sound detecting device adapted to detect heart sounds and to produce a signal corresponding to an amplitude of said detected heart sounds over time.

An implantable medical device for determining a cardiac status of a patient, said medical device being connectable to at least one medical lead for contact with tissue of a heart of said patient, said device comprising:

• a sensor arrangement adapted to sense cardiac signals related to mechanical activity of said heart and to produce an output signal related to the mechanical activity;
• an activity level sensor arrangement adapted to sense an activity level of said patient;
• a cardiac event identifying module adapted to identify predetermined cardiac events in the cardiac signals and to determine a systolic time interval and a diastolic time interval of a cardiac cycle using said identified cardiac events;
• a calculation module adapted to calculate a percentage of left ventricular diastolic time (PLVDT) for a cardiac cycle corresponding to a relation between a diastolic time interval and a cardiac cycle time interval using said determined systolic and diastolic time intervals or a percentage of left ventricular systolic time (PLVST) for a cardiac cycle corresponding to a relation between a systolic interval time interval and a cardiac cycle time interval using said determined systolic and diastolic time intervals, wherein said calculation module is adapted to determine a rate of change of said PLVDT (or PLVST) and said activity level;
• and
• a cardiac status determining module adapted to synchronize the activity level with said calculated PLVDT (or PLVST) over time and to determine a cardiac status based on said calculated PLVDT (or PLVST) and on said activity level and on a rate of change of said PLVDT (or PLVST) and on a rate of change of said activity level;
• wherein PLVDT=LVDT/(LVDT+LVST) and PLVST=LVST/(LVDT+LVST);
• wherein said sensor arrangement includes an IEGM device adapted to sense electrical signals of said heart and to produce an IEGM signal;
• and
• wherein said cardiac event identifying module is adapted to synchronize said IEGM signal with heart sound amplitude signals, and to use an identification of a cardiac event in the IEGM signal to identify first and second heart sounds.