Implantable cardiac stimulation device with respiratory modulated therapy delivery

A method comprising:

• sensing cardiac electrical activity using at least one implantable sensing electrode;
• generating and delivering stimulation that induce cardiac depolarizations to patient tissue;
• evaluating cardiac electrical activity signals sensed by the at least one implantable sensing electrode and utilizing a series of polarization amplitudes within the signals as a cardiac based respiration indicator to monitor cyclical variations corresponding to respiration;
• and
• controlling timing of delivery of the stimulation according to one or more therapy parameters based at least in part on the cardiac based respiration indicator wherein the inducing is performed by an implanted processor;
• wherein the parameters comprise a timing parameter and wherein controlling comprises modulating the parameters with the respiration by extending the timing parameter during exhalation phases and shortening the timing parameter during inspiration phases.