METHOD FOR DETERMINING AND MONITORING A CARDIAC STATUS OF A PATIENT

摘要

The present invention relates to a method for accurately and reliably determining a cardiac status of a patient. An implantable medical device, IMD, comprises a sensor arrangement adapted to sense signals related to mechanical activity of the heart and an activity level sensor arrangement adapted to sense an activity level of the patient. Further, the IMD calculates 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 the 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. A cardiac status is determined based on the calculated PLVDT (or PLVST) and on an activity level of the patient.

主权项

1. A method for determining a cardiac status of a patient in an implantable medical device being connectable to at least one medical lead for contact with tissue of a heart of the patient, the method comprising:
sensing signals related to mechanical activity of the heart and producing an output signal related to the mechanical activity; sensing an activity level of the patient; identifying predetermined cardiac events in the cardiac signals and determining a systolic time interval and a diastolic time interval of a cardiac cycle using the identified cardiac events; calculating 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 the 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 the determined systolic and diastolic time intervals; calculating a rate of change of the PLVDT (or PLVST) and the activity level; synchronizing the activity level with the calculated PLVDT (or PLVST) over time; and determining a cardiac status based on the calculated PLVDT (or PLVST) and on the activity level and on a rate of change of the PLVDT (or PLVST) and on a rate of change of the activity level.