TORONTO – Two Toronto law firms have launched a Canada-wide class-action lawsuit against the manufacturers of implantable defibrillators that can fail with little or no warning because of potentially defective batteries.About 8,000 Canadians were implanted with the cardiac defibrillators with the brand names Fortify, Fortify Assura, Fortify Assura MP, Unify, Unify Assura, or Unify Quadra, which were manufactured between January 2010 and May 23, 2015. Those made after that period are not affected by the defect.U.S.-based manufacturer St. Jude Medical Inc. and subsidiary St. Jude Medical Canada Inc. are named as defendants in the multimillion-dollar class-action suit, which has been filed with Ontario Superior Court, said Paul Miller, a partner in the law firm Howie, Sacks & Henry.Miller, whose company teamed up with law firm Waddell Phillips to launch the legal action, said the court has to first certify the case as a class-action, which he hopes will occur by late fall. He said a similar class-action suit in the U.S. is also in preliminary stages.Both Health Canada and the U.S. Food and Drug Administration have issued warnings about the St. Jude devices, which automatically shock the heart into normal rhythm in people who have potentially life-threatening cardiac arrhythmias or heart failure.Those warnings were in response to the discovery that some of the devices’ batteries developed a lithium cluster formation, causing them to short-circuit and their power to rapidly deplete, leading to premature failure.Two European patients who had the defibrillators implanted in their chests died when the batteries failed, one of them just days before a planned surgical replacement. In Canada, there have been more than two dozen reports of patients losing consciousness due to lack of blood to the brain after their devices faltered.St. Jude Medical was purchased in January by Chicago-based Abbott Laboratories for about US$25 billion.In an emailed statement Thursday, an Abbott spokesperson said the company plans to “defend its position” in the pending Canadian class-action lawsuit, and noted that “the safety and quality of Abbott’s products is our top priority.”The representative patient plaintiff in the suit is Shirley Houle of Port Hope, Ont., who had a Fortify Assura defibrillator implanted in January 2014. According to the statement of claim submitted to the court, Houle was informed by doctors about the potential for her defibrillator to fail in October 2016, leaving her “enormously distraught and anxious” and fearful to drive by herself or to travel outside Canada.Her husband Roland is named as the representative plaintiff under the Family Law Act for damages suffered as a result of injuries and losses suffered by his wife, the statement of claim says.Houle’s defibrillator, which was not supposed to require replacement for another four years, was surgically removed in March and replaced with a different model.“You are causing someone to have a surgery at an earlier stage and at least an extra surgery,” said Miller. The lawsuit claims St. Jude Medical breached its duty of care in failing to warn patients, doctors and government regulators about the potentially serious defect in the devices.The defibrillators, introduced in 2010, are meant to last for at least seven years before their batteries deplete and the products need replacing. They are designed to vibrate at regular intervals once power begins to decline, a signal that patients should see their doctors about a replacement within 90 days.“Obviously, if you have an implanted device and you can have the battery deplete without any warning, it could be a serious problem,” said Miller.Last October, St. Jude Medical notified doctors about the defective battery in some of their defibrillators, which had been implanted in almost 400,000 patients worldwide. Following a recall of the products, 841 were returned to the company because their batteries had unexpectedly failed.But in an April 12 letter to St. Jude Medical, the FDA said the company had played down the battery failure and continued shipping the defibrillators from its Sylvan, Calif., plant for years before the devices were recalled last fall.The FDA also said the device maker had not shown it was taking sufficient action to repair the defects and ordered the company to provide a new reporting plan.However, Abbott’s spokesperson said Thursday the company has “worked to provide consistent updates to regulatory authorities and our global customers around ongoing analysis of performance data from the affected device population.“Recently, the company analyzed affected devices that were returned for product analysis due to premature battery depletion. Importantly, the rates of patient impact remain low and to date, the adverse event rates have shown no indication of acceleration.”– Follow @SherylUbelacker on Twitter.