In a method to predict the diastolic rest period in the cardiac cycle of a patient under examination, the linear relation between heart rate and position of the diastolic rest period in the cardiac cycle is determined by determining the position of the diastolic rest period in at least two different heart rates of the examined patient, determining the breathing motion using rate and/or acceleration sensors and predicting the next diastolic rest period under consideration of the breathing motion and the definite relation between the heart rate and the position of the diastolic rest period of the patient under examination.