Patent ID: 7539539

Claim:
An implantable cardiac stimulation device comprising: an implantable stimulation pulse generator; at least one implantable stimulation electrode connected to the stimulation pulse generator; at least one implantable sensing electrode arranged to sense cardiac electrical activity; and a controller receiving cardiac electrical activity signals from the at least one sensing electrode wherein the controller is in communication with the pulse generator so as to selectively induce the pulse generator to provide indicated therapeutic cardiac stimulations via the at least one stimulation electrode according to one or more therapy parameters and wherein the controller evaluates cardiac electrical activity signals sensed by the at least one implantable sensing electrode and utilizes a series of polarization amplitudes within the signals as a cardiac based respiration indicator to monitor cyclical variations corresponding to respiration and wherein at least one of the parameters comprises an interval and wherein the interval is varied such that it is elongated during expiration phases of respiration and shortened during inspiration phases of respiration.