By Christopher Williams,Staff Writer

LEWISTON – Dr. Daniel Soroff rested the wandlike device over the patient’s collarbone. A strand of wires looped across the patient’s shoulder and fed into a special portable computer.

Soroff, a cardiac electrophysiologist at Central Maine Medical Center, was quizzing and reprogramming an implanted defibrillator.

The procedure, which took about 15 minutes, was needed to prevent the unit from possibly malfunctioning, said Soroff, the only CMMC doctor who performs the implants.

Three of his patients were told they needed the unplanned hospital visit after the company that made the pager-sized machines announced a recall last week. It was Guidant Corp.’s third recall this month, covering seven defibrillator models in all.

On Friday, the company voluntarily recalled its latest models, including the CONTAK RENEWAL 3 HE, H177. Soroff has implanted three patients with that model.

Of the 46,000 defibrillators in use, only four have reportedly malfunctioned as of June 23, the Indianapolis-based company said in a written advisory to doctors. A fifth occurrence was reported but has not been confirmed. All four patients had new units installed. None had been injured.

Without reprogramming, a switch could end up stuck in the “off” position if its carrier were to encounter a large magnetic field, Soroff said. That would render the defibrillator ineffective if that carrier were to later experience an irregular heart rhythm, a condition that, in some cases, could result in death.

The unit also functions as a pacemaker, designed to maintain a normal heart rhythm. That function is unaffected by the position of the switch, he said.

The procedure performed by Soroff will likely shorten the life of the unit by about 15 percent, or about one of its roughly six years, he said.

The failure rate of the unit is estimated to be less than one in 10,000, Soroff said. Reprogramming “will remove any serious risk from those three patients,” he said. The patients will not be billed for the extra doctor’s visit, he said.

At least three other companies make defibrillators, Soroff said. He chose Guidant because none of that company’s units had been recalled before he installed them. Other manufacturers had announced recalls.

“It’s never an easy choice,” he said, adding he doesn’t make it “lightly.”

At Maine Medical Center in Portland, roughly 100 patients were implanted with one of the seven models flagged in three different recalls by Guidant, hospital spokesman Wayne Clark said. The patients were treated by doctors from two Portland cardiology groups affiliated with MMC. About 360 such units are implanted in patients every year, Clark said.

Guidant Corp. was in the news earlier this month when it recalled about 50,000 implanted defibrillators that had short-circuited or malfunctioned. Guidant said two patients implanted with one of the devices identified in the original recall have died.

Doctors at a cardiology group affiliated with Eastern Maine Medical Center could not be reached for comment.