Transvenous pacemakers in children: relation of lead length to anticipated growth.

Although transvenous pacing is feasible in infants and children, uncertainty remains as to how to allow for future growth at the time of lead insertion. Accordingly, we retrospectively reviewed the relation between age and transvenous lead length. Standard posteroanterior chest roentgenograms were reviewed for 26 patients with transvenous pacemakers inserted at Babies Hospital and Presbyterian Hospital between 1985 and 1989. Sixteen of these were children (age range, 0.75 to 15 years) and 10 were adults (age range, 27 to 90 years). The intravascular length of right ventricular pacing leads was measured as projected on the roentgenogram. In 10 children, the presence of lead loops in the right atrium required the lead length that would have resulted from conventional placement to be estimated. Results for right ventricular pacing lead lengths were correlated with age using linear regression analysis. Average uncorrected lead length measured on the roentgenogram was 345 +/- 35 mm (standard deviation) in adults and 222 +/- 51 mm in children. The use of right atrial loops increased implanted lead length by an estimated 79 mm, from 188 +/- 26 to 267 +/- 43 mm. The difference between lead length in children and adults was analyzed. Approximately 190 mm of additional right ventricular pacing lead in infants and 100 mm in 10-year-old children was needed for growth to adult size. We conclude that an 80-mm right atrial lead loop will allow 6 to 12 years (mean, 8 years) of growth in infants and children without the need for reoperation to adjust lead length.