Implantable cardioverter-defibrillators (ICDs) are lifesaving devices. Over 100,000 patients received ICDs in 2004 at a cost of $2 billion for the pulse generators alone. Because of expanded indications and coverage by Medicare, the number of ICD implantations and replacements is expected to increase dramatically during the next decade. The average ICD patient at our institution now lives nearly 10 years after the procedure. However, the service life of pulse generators has decreased from 4.7 +/- 1 year for single-chamber units to 4.0 +/- 1 year for dual-chamber devices. This mismatch between patient longevity and the service life of ICDs poses a significant clinical and economic burden that must be addressed. One near-term solution is for manufacturers to provide devices with larger batteries so that most patients can have an ICD pulse generator that lasts a lifetime. For the long-term, more robust or renewable energy sources are needed.