Patent ID: 8391976

Claim:
An active implantable medical device for treating a heart failure condition with cardiac resynchronization therapy (CRT) and/or with synchronized stimulation, comprising: an effort sensor providing an output signal representative of a current level of a patient's effort; and a CRT pacemaker having electrodes configured to determine a spontaneous frequency (f sp ) of a patient in the presence of a sinus rhythm and control logic configured to detect a beginning of the patient's effort from the output signal, stimulation frequency varying between a base frequency (f base ) and a maximum frequency (f max ) according to the output signal, and selectively delivering stimulation pulses according to said effort stimulation frequency, said control logic selectively delivering stimulation pulses for CRT via incrementing said delivered pulse stimulation frequency by: determining a target frequency based on a difference between a first frequency and the maximum frequency (f max ), wherein the first frequency is the higher frequency of the base frequency (f base ) and the spontaneous frequency (f sp ); and increasing, in response to a detection of the beginning of the patient's effort, the stimulation frequency from an initial value or the spontaneous frequency to said target frequency in a predetermined time period corresponding to the time period of no more than four cardiac cycles.