An implantable rate adaptive cardiac rhythm management system configured for applying stimuli to a patient's heart, the pacing stimuli defined by pacing parameters, the system comprising: an implantable medical device comprising an implantable pulse generator configured to generate an electrical stimulus to be delivered to a patient's heart according to a first set of pacing parameters including a lower rate limit setting, the pulse generator including a control system configured to: acquire a coronary venous pressure signal from a pressure sensor implanted in a coronary vein (30, 32) of the patient; calculate an average coronary venous end diastolic pressure (CV-EDP) value from the CVP signal; monitor the average CV-EDP value over a predetermined interval; and dynamically adjust the LRL setting responsive to the detection of a first or a second predetermined event based on the average CV-EDP value, wherein the LRL is a pacing rate at which the pulse generator delivers pacing stimuli in the absence of sensed intrinsic cardiac activity and the control system is configured to increase the LRL setting in response to detecting the first predetermined event and reduce the LRL setting upon detecting the second predetermined event, wherein the first predetermined event is detected based on an increase in the average CV-EDP value above a programmed threshold value indicative of an onset of early decompensation symptoms; the system further comprising: a plurality of implantable medical electrical leads configured to sense cardiac electrical activity and to deliver the pacing stimuli, at least on of the leads being configured for chronic implantation within a coronary vein of the patient's heart and including the pressure sensor configured to generate a CVP signal indicative of fluid pressure within the coronary vein. acquire a coronary venous pressure signal from a pressure sensor implanted in a coronary vein (30, 32) of the patient; calculate an average coronary venous end diastolic pressure (CV-EDP) value from the CVP signal; monitor the average CV-EDP value over a predetermined interval; and dynamically adjust the LRL setting responsive to the detection of a first or a second predetermined event based on the average CV-EDP value, wherein the LRL is a pacing rate at which the pulse generator delivers pacing stimuli in the absence of sensed intrinsic cardiac activity and the control system is configured to increase the LRL setting in response to detecting the first predetermined event and reduce the LRL setting upon detecting the second predetermined event, wherein the first predetermined event is detected based on an increase in the average CV-EDP value above a programmed threshold value indicative of an onset of early decompensation symptoms; the system further comprising: a plurality of implantable medical electrical leads configured to sense cardiac electrical activity and to deliver the pacing stimuli, at least on of the leads being configured for chronic implantation within a coronary vein of the patient's heart and including the pressure sensor configured to generate a CVP signal indicative of fluid pressure within the coronary vein. a plurality of implantable medical electrical leads configured to sense cardiac electrical activity and to deliver the pacing stimuli, at least on of the leads being configured for chronic implantation within a coronary vein of the patient's heart and including the pressure sensor configured to generate a CVP signal indicative of fluid pressure within the coronary vein.