Oversensing of transthoracic excitation stimuli in contemporary pacemakers

BackgroundTransthoracic impedance measurements (TIM) is primarily used for minute ventilation rate adaptive sensors in pacemakers. With elevated impedance, the TIM electrical signal itself is oversensed, causing device malfunction. ObjectiveWe report an increased incidence of TIM oversensing. MethodRetrospective chart review. We review existing records of 18 patients who have demonstrated device malfunction with TIM oversensing. ResultsWe have found a 1.8% incidence of TIM-related oversensing in our patient population of 959 patients with contemporary Boston Scientific (Marlborough, MA, USA) pacemakers and cardiac resynchronization therapy pacemakers. One patient experienced a syncopal episode. ConclusionOversensing with pacing inhibition is apparent with the potential of adverse effects to patients.