System and method for evaluating diastolic function based on cardiogenic impedance using an implantable medical device

A method for use with an implantable medical device for implant within a patient, the method comprising:

• measuring values representative of ventricular cardiogenic impedance and deriving E-wave parameters representative of passive filling of the ventricles of the heart of the patient from the ventricular cardiogenic impedance values, wherein deriving E-wave parameters from the ventricular cardiogenic impedance values includes:
• generating an E-wave impedance template representative of passive filling of the ventricles based on ventricular cardiogenic impedance values measured during an initial period of non-demand pacing, with the period of non-demand pacing including atrial pacing at a rate sufficient to trigger an artificial 2:1 block to emphasize active and passive filling contributions to diastolic function;
• measuring additional values representative of ventricular impedance during a subsequent cardiac cycle to be examined;
• and
• determining a convolution of the E-wave impedance template with the additional ventricular impedance values to derive E-wave parameters representative of passive filling contributions to diastolic function within the subsequent cardiac cycle;
• measuring values representative of atrial cardiogenic impedance and deriving A-wave parameters representative of active filling of the ventricles from the atrial cardiogenic impedance values;
• assessing diastolic function based on the E-wave parameters and the A-wave parameters;
• and
• controlling at least one device function based on the assessment of diastolic function.