Greg Jesse was proudly watching his son play football when he felt a thump in his chest. Seconds later he felt another thump—which doubled him over in pain—and then another. That last one knocked him unconscious.

This was not what he expected from the implanted device in his heart—a heart defibrillator made by St. Jude Medical, meant to restore his heart to normal beating after it went into an abnormal heart rhythm. These implanted defibrillators have saved hundreds of thousands of lives since their invention, but, apparently, not without occasional glitches.

The problem with St. Jude’s device was its Riata-brand leads, which are the wires that connect the implanted computer (about the size of a stopwatch) to the heart. The leads have to be threaded into the heart, with a silicone-like coating protecting the raw metal of the wires from shocking the body. On the Riata leads, St. Jude was using a coating that it said was much more resilient than ordinary silicone. But after a few years, problems with the Riata leads began surfacing, including some very scary, dangerous ones.

The wires were working their way out of their covering and perforating the heart. In at least one instance, a lead was almost poking through a patient’s skin. Many of the 128,000 patients with the implants were getting severe shocks that caused great pain. In addition, the defects sometimes prevented implants from performing their original purpose—delivering a jolt to the heart when it was needed (at least 20 patients died this way). Initially, St. Jude warned doctors that the overall rate of abrasion was tiny, with just .47 percent of Riata leads affected, but doctors studying the problem warned of a significantly greater failure rate, up to 30 percent in some reports.

Patients with the St. Jude devices faced a tough decision: Leave the leads alone and risk pain or even death, or remove the leads, which is a dangerous operation. If the detached lead perforates the heart tissue during removal, the patient could die. In many instances, the leads have been overgrown with heart tissue and removing them can damage the heart, or broken pieces of the wire could be left behind inside veins. Patients turned to lawyers for recourse, and scores of class-action suits have been filed. (Investors also want in on the action: A class action filed against St. Jude charges that it withheld information that would affect the firm’s stock price.)

And there the issue now sits. St. Jude, the nation’s second-largest cardiac- rhythm product company, stopped selling the two defibrillator models using Riata leads in 2010. In 2011, the FDA issued a Class I Medical Device Recall, citing a reasonable probability that use of the product would cause serious adverse health consequences or death. St. Jude wouldn’t talk to Twin Cities Business about the issue, but has insisted that it acted appropriately in warning doctors of the Riata lead problems. But, according to the New York Times, many experts in the field think the company was slow to warn of the lead problem. And, says the Times, the crucial data highlighting the problems came from outside experts and not from St. Jude’s own monitoring systems. In that, this episode is similar to recent ones from St. Jude competitors Medtronic and Guidant (now Boston Scientific) involving similar critical product flaws. And, ominously for St. Jude, both those firms settled their lawsuits for amounts in the hundreds of millions of dollars.