An implantable medical device has a pressure sensing arrangement to measure right ventricular pressure of a heart including a pressure sensor adapted to be positioned in the right ventricle of the heart, to measure the pressure and to generate a pressure signal in response to the measured pressure. The pressure sensing arrangement also has a pressure signal processor and a timing unit. The processor determines from the pressure signal, using diastolic timing signals from the timing unit based on the pressure signal identifying the diastolic phase, a diastolic pressure signal representing the ventricular pressure only during the diastolic phase of the heart cycle.