Commentary on Implantable Cardioverter-Defibrillators in Children: Innovation to Design a Pediatric Implantable Cardioverter-Defibrillator—Children as the NASCAR of Device Development

DOI: 10.19102/icrm.2011.020203

GEORGE F. VAN HARE, MD

Director, Pediatric Cardiology, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, MO

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The author reports no conflicts of interest for the published content.
Manuscript received January 12, 2011, final version accepted January 20, 2011.

Address correspondence to: George F. Van Hare, MD, Director, Pediatric Cardiology, St. Louis Children's Hospital, Washington University School of Medicine, One Children's Place, Campus Box 8116 – NWT, St. Louis, MO 63110. E-mail: vanhare@kids.wustl.edu

In this issue of The Journal of Innovations in Cardiac Rhythm Management, Drs. Berul and Moak provide an excellent review of the issues facing pediatric electrophysiologists who must implant and manage implantable cardioverter-defibrillators (ICDs) in children. They point out the fact that innovations in device therapy for arrhythmias are almost entirely driven by the adult market. This is not surprising, considering that children make up only 1% or so of the device population. Historically, innovation in pediatric device therapy has mainly consisted of imaginatively adapting devices originally designed for the adult market and then working out ways to use them effectively in our patient population. Berul and Moak conclude with a “wish list” of areas where industry could help the pediatric electrophysiologist with directed development of new devices.

It is certainly true that the flow of technological innovation is usually from the adult application to the pediatric (or congenital heart disease) application. However, there are interesting examples of innovation flowing in the opposite direction. The best example is the Medtronic (Minneapolis, MN) steroid-eluting epicardial pacing lead, which was developed to solve a primarily pediatric problem: the high post-implant pacing thresholds and exit block in children who are not candidates for a transvenous system, either due to size or anatomy.^1,2 A side effect is that the availability of these leads broadens the capabilities of all adult electrophysiologists, as they now provide a route to left ventricular pacing in individuals who have difficult or unpromising coronary sinus anatomy. There is an important principle here: innovations directed to solve problems in small groups of patients often find application, once available, more generally. The phenomenon, of course, is not strictly medical. Consider the effect of the Americans with Disabilities Act³: accommodations meant to improve access for handicapped individuals (e.g. curb cuts, wheelchair ramps, and elevators) benefit a larger population (parents with strollers, the beer delivery guy, etc.). Similarly, in a different venue, automotive companies are active in developing new technology for use on the race track. Designs that are shown to work there, in that narrow application, migrate to production line models and improve their performance.

Most children are naturally more active than adults, and certainly are more active than the typical adult receiving an ICD. Consequently, the stress placed on the system, and especially on the leads, is much greater with a pediatric implant. This can lead to a higher rate of lead malfunction and fracture in the pediatric implanted population. This was certainly the case with the Sprint Fidelis (Medtronic) lead recall.⁴ However, lead fractures are a big problem in patients of all ages, and their extraction poses a significant potential hazard to all. Designs that perform well in the pediatric population would certainly be the superior choice for patients of all ages and sizes. Again, the situation is similar to the use of the race track for testing new automotive designs: testing in the high-stress environment of the race track leads to safer and more reliable products for the general population.

All of this means that if device companies desire to develop innovative tools for new applications and to make their products as safe and reliable as possible, they should look to the pediatric population, as Detroit looks to NASCAR.

References

Hamilton R, Gow R, Bahoric B, Griffiths J, Freedom R, Williams W. Steroid-eluting epicardial leads in pediatrics: improved epicardial thresholds in the first year. Pacing Clin Electrophysiol 1991; 14:2066–2072. [CrossRef] [PubMed]
Tomaske M, Gerritse B, Kretzers L, et al. A 12-year experience of bipolar steroid-eluting epicardial pacing leads in children. Ann Thorac Surg 2008; 85:1704–1711. [CrossRef] [PubMed]
Essex-Sorlie D. The Americans with Disabilities Act: I. History, summary, and key components. Acad Med 1994; 69:519–524. [PubMed]
Krahn AD, Champagne J, Healey JS, et al. Outcome of the Fidelis implantable cardioverter-defibrillator lead advisory: a report from the Canadian Heart Rhythm Society Device Advisory Committee. Heart Rhythm 2008; 5:639–642. [CrossRef] [PubMed]