Inappropriate rate response in a leadless pacemaker due to automatic rate profile optimization

A three-axis accelerometer sensor is incorporated in a leadless pacemaker (Micra, Medtronic(Inc)) for rate adaptation. Three sensor setpoints at lower rate (LR), activity of daily living rate (ADLR), and upper rate (UR) are used to convert detected acceleration to a desired rate response. We describe inappropriate rate acceleration at rest and during chest physiotherapy in a sedentary elderly patient with leadless pacemaker. The underlying mechanism and various programming options are discussed.