In a major high-tech irony for the medical device world, wireless implantable defibrillators generally rely on landlines to ultimately transmit their data to doctors. And a CDC report says that reality is limiting the technology's use in one-third of all U.S. households, The Wall Street Journal's "Health Blog" reports. The reason: Households are rapidly abandoning landlines as cell phone technology has become ubiquitous. Existing monitors generally depend on plugging into landlines at home to download information from the defibrillators as patients sleep, relaying patient data to the devicemakers themselves who then shunt it to the doctors through company-run websites. Companies, such as Medtronic ($MDT) and St. Jude Medical ($STJ), have had FDA approval for cellular accessories for their monitoring systems since 2010, but it is unclear who would cover the cost of the adapters, which has dampened their use. And regulators have resisted industry attempts to expand bandwidth, the article notes. Blog