Patent ID: 8805497

Claim:
A cardiac device, comprising: one or more sensing amplifiers for forming sensing channels for sensing electrical cardiac activity; one or more pulse generators for forming pacing channels for delivering pacing pulses to one or more myocardial sites; a controller programmed to operate the device in either a normal operating mode or an intermittent pacing therapy (IPT) mode; wherein, in the IPT mode, the controller is programmed to deliver paces to the one or more myocardial sites using a pacing mode that results in some degree of ventricular dyssynchrony as compared with the normal operating mode; wherein the controller is programmed to: switch to the IPT mode according to a timed duty cycle schedule in which the device operates in the IPT mode for A seconds and operates in the normal mode for B seconds; set the IPT duty cycle duration values A and B as functions of a sensed or paced heart rate in which different heart rate values correspond to different duty cycle duration values and such that the IPT duty cycle duration value A is decreased in response to an increase in heart rate; and, deliver paces during the IPT mode at a pacing rate that is a specified percentage above the sensed heart rate wherein the specified percentage varies inversely with sensed heart rate.