PORTLAND, Ore. (KATU) — A Portland man is seeking nearly $534 million in damages in a lawsuit that alleges Kaiser Permanente and several doctors failed to properly diagnose and treat his heart condition, leading to a cardiac arrest and life-altering injuries, including the amputation of both legs.
The lawsuit, filed Aug. 21, 2026, was brought by Portland attorney Mark Johnston on behalf of plaintiff Mathew Williamson. It alleges “negligence and recklessness” by the defendants caused Williamson to suffer cardiac arrest and severe complications, including “above knee amputation of both of Matthew’s legs,” fasciotomies on both arms with “severe loss of function,” and other medical complications.
According to the complaint, Williamson had a history of cardiac issues that required constant monitoring by cardiac providers, including a history of AV block that “progressively worsened over time.” The lawsuit says health care providers started him on metoprolol, and alleges the medication “is not appropriate for those with serious AV block.” The complaint further alleges that if metoprolol is used with a patient with serious AV block, “then a pacemaker is necessary.”
The lawsuit states that in the time period leading up to May 15, 2025, the defendants were “fully aware” of Williamson’s cardiac issues, diagnosis and test results. It alleges that on May 15, 2025, Williamson suffered a cardiac arrest that resulted in severe damage to his body, including the eventual above-the-knee amputations and serious complications to his arms that required fasciotomies and led to loss of function.
The complaint says Williamson continues to receive care and treatment due to complications and trauma it attributes to the defendants’ actions. It also lists additional alleged injuries and complications, including additional cardiac complications, renal failure, bowel injury with ileostomy, phantom limb pain, and severe physical and emotional injuries.
The lawsuit seeks noneconomic damages “in an amount to be determined by a jury, but not to exceed $500,000,000.” It also seeks past medical expenses of approximately $2,716,202.90 and estimated future medical expenses of $30,000,000, along with past lost income of $85,000 and an estimated $1 million in impaired earning capacity. The complaint also requests 5% pre-judgment interest for economic losses, plus costs and disbursements.
KATU News reached out to Kaiser Permanente for a response.