Patent ID: 8478403

Claim:
For use with an implantable system, a method for monitoring and modifying a patient's arterial blood pressure without requiring an intravascular pressure transducer, the method comprising: (a) for each of a plurality of periods of time per day during which the patient's heart is being paced, (a.1) obtaining a signal indicative of electrical activity of the patient's heart, and a signal indicative of changes in arterial blood volume remote from the patient's heart; (a.2) detecting one or more predetermined features of the signal indicative of electrical activity of the patient's heart, and one or more predetermined features of the signal indicative of changes in arterial blood volume remote from the patient's heart; (a.3) determining one or more metrics indicative of pulse arrival time (PAT), each metric indicative of PAT determined by determining a time from one of the detected features of the signal indicative of electrical activity of the patient's heart to one of the detected features of the signal indicative of changes in arterial blood volume remote from the patient's heart; and (a.4) estimating the patient's arterial blood pressure based on at least one of the one or more metrics indicative of PAT; (b) monitoring changes in the patient's arterial blood pressure based on the estimates of the patient's arterial blood pressure wherein the monitoring comprises monitoring a circadian variability of the patient's arterial blood pressure; and (c) modifying the patient's arterial blood pressure by adjusting at least one pacing parameter and/or pacing configuration based on the monitored changes in the patient's arterial blood pressure, wherein the modifying comprises adjusting at least one pacing parameter and/or pacing configuration to increase the circadian variability if the circadian variability is below a first threshold, and adjusting at least one pacing parameter and/or pacing configuration to decrease the circadian variability if the circadian variability is above a second threshold.