Failure of electrocardiographic monitoring to detect cardiac arrest in patients with pacemakers

J. R. Brownlee, G. A. Serwer, M. Dick 2nd, T. Bauld and A. Rosenthal
Department of Pediatrics, C. S. Mott Children's Hospital, University of Michigan, Ann Arbor 48109.

Two children with cardiac pacemakers are described who experienced cardiorespiratory arrest not detected by the electrocardiographic (ECG) monitor. The pacemaker stimuli were interpreted by the monitor as a QRS complex with inhibition of the heart rate alarm, demonstrating the need for reliable non-ECG monitoring in patients with pacemakers. A review of all deaths in children with pacemakers in the last ten years also shows the high association of respiratory failure in patients with congenital heart disease and a pacemaker, underscoring this need. Various non-ECG monitoring modalities are discussed. Finally, analysis of the ECG monitor characteristics contributing to inappropriate sensing of the pacemaker stimulus was performed, showing the direct relation between the pacemaker stimulus amplitude seen by the monitor and the monitor sensitivity with inappropriate sensing, and the inverse relation between the monitor bandwidth and inappropriate sensing. Recommendations for monitor adjustment when monitoring patients with pacemakers are provided.