PERMANENT PACING IN CHILDREN - ACUTE LEAD IMPLANTATION AND LONG-TERM FOLLOW-UP

Optimal pacing in children mandates the proper selection of the pacing electrode system and appropriate follow-up testing. This review discu sses factors that influence electrode selection, acute and chronic thr esholds to be expected from each electrode type, electrode longevity i n the child, and appropriate follow-up techniques applicable to the pe diatric patient. Much information in this article is drawn from the Mi dwest Pediatric Pacemaker Registry. Epicardial electrode implantation has been the classic mode of electrode implantation used in children, but the endocardial approach has been increasingly used. At the curren t time, epicardial electrodes account for similar to 60% of electrodes implanted in children. Factors that require use of epicardial over en docardial pacing are small size of the patient, lack of venous access to the ventricle, the presence of right-to-left intracardiac shunting with risk of systemic embolization, and/or clotting abnormalities with an increased risk of large pulmonary emboli or the development of ven a caval obstruction. The minimum size of the child deemed appropriate for endocardial pacing is controversial. Smaller electrode and generat or size have decreased the lower age and weight at which endocardial i mplantation can be performed. However, the long-term consequences of l ong-term endocardial pacing in children is unknown. The most common so urce of epicardial electrode malfunction is electrode fracture, and th e average longevity is 8.3 years. Long-term endocardial electrode fail ure is due predominantly to electrode fracture, with an average longev ity > 9 years. Finally, follow-up techniques are critical to ensure co ntinued appropriate pacemaker system function because the underlying e lectrophysiological state may change. Follow-up techniques include pac emaker interrogation and threshold testing at the time of pacemaker cl inic visit, ambulatory electrocardiographic monitoring, transtelephoni c electrocardiographic monitoring and exercise testing. All techniques need to be used to ensure appropriate pacemaker function and programm ing.