Patent ID: 8428698

Claim:
For use with an implantable system, a method comprising: (a) using an implanted sensor to obtain a signal indicative of changes in a patient's arterial blood volume for a period of time corresponding to one or more cardiac cycles; (b) using implanted electrodes to obtain a signal indicative of electrical activity of the patient's heart for the period of time; (c) detecting a beginning of a diastolic period (DP) based on a feature of the signal indicative of changes in arterial blood volume; (d) detecting an end of the DP based on a feature of the signal indicative of electrical activity of the patient's heart; and (e) estimating the DP, an isovolumic relaxation time (IVRT) and/or a diastolic filling time (DiFT) based on the beginning of the DP as detected at step (c) and the end of the DP as detected at step (d).