A device for reducing blood pressure of a patient having a pretreatment blood pressure and a pretreatment ventricular filling volume, comprises:- a stimulation circuit configured to deliver a stimulation pulse to at least one cardiac chamber； and- a processor circuit coupled to the stimulation circuit, the processor circuit configured to operate in an operating mode in which at least one of the cardiac chambers is stimulated to cause a ventricular excitation to commence between about 0 ms and about 70 ms after the onset of atrial excitation, thereby reducing the ventricular filling volume from the pretreatment ventricular filling volume and reducing the patient's blood pressure from the pretreatment blood pressure.
