A COMPARISON OF 2 STAB-ON UNIPOLAR EPICARDIAL PACING LEADS IN CHILDREN

The Oscor MP52V and Medtronic 4951 leads have similar construction and intended application. To determine if one of these designs was more s uited to pediatric pacing, we reviewed implant, 3 month, and 12 months follow-up thresholds for all 18 MP52V implants at our institution fro m December 1989 to April 1991 and compared them to the 4951 implants f rom January 1982 to October 1989. Lead survival for the MP52V implants was compared to the most recent 36 4951 implants. Patients ranged in ages from 2 days-16 years (median = 4 years) and required antibradycar dia pacing for congenital or acquired heart disease. Patients were com pared for weight and proportion of atrial leads in each group by t-tes t and Fisher exact tests respectively Energy thresholds were assessed in mu J and compared by t-test. Lead survival was defined by abandonme nt or replacement for any reason. Kaplan & Meier survival curves were plotted and compared by Gehan's Wilcoxan Test. There were no significa nt differences between the MP52V and 4951 groups for age at implant (5 3 months vs 80 months) or proportion of atrial implants (5/18 vs 11/36 ). Lead survival was poor but did not differ significantly (70% vs 78% cumulative survival at 3 years), usually failing by exit block. Impla nt and follow-up thresholds did not differ significantly between leads . The MP52V did not provide significant improvement in performance ove r the 4951. New epicardial lead designs are needed to improve lead sur vival and thresholds in children.