Patent ID: 7672725

Claim:
A cardiac rhythm management system, comprising: a sensing circuit to sense a cardiac signal; a heart rate variability (HRV) measurement circuit, coupled to the sensing circuit, to measure an HRV being a variance in cardiac cycle lengths over a predetermined period of time based on the sensed cardiac signal and to produce an HRV parameter representing the measured HRV; a pacing output circuit to deliver pacing pulses; and a stimulation control circuit coupled to the sensing circuit, the HRV measurement circuit, and the pacing output circuit, the stimulation control circuit including: a stimulation algorithm execution module to control the delivery of the pacing pulses by executing at least a first stimulation algorithm, the stimulation algorithm execution module adapted to control the delivery of the pacing pulses by executing one of a cardiac resynchronization therapy (CRT) pacing algorithm and a remodeling control therapy (RCT) pacing algorithm; and a safety check module adapted to dynamically adjust a first safety threshold using an indication, estimation, or prediction of an activity level and including: a comparator adapted to compare the HRV parameter to the first safety threshold; and a switch circuit adapted to stop the execution of the RCT pacing algorithm and start the execution of the CRT pacing algorithm when the HRV parameter falls below the first safety threshold.