• Senator John Fetterman experienced a significant ventricular fibrillation episode that required his implanted defibrillator to activate
  • The Pennsylvania Democrat, who has a history of cardiomyopathy and atrial fibrillation, is expected to make a full recovery
  • The incident represents the most serious cardiac event Fetterman has faced since his 2022 stroke and subsequent pacemaker-defibrillator implantation

Senator John Fetterman's implanted defibrillator activated to address a "ventricular fibrillation flare-up" earlier this week, according to people familiar with his medical condition, marking the most serious cardiac episode the Pennsylvania Democrat has faced since his near-fatal stroke during his 2022 Senate campaign.

The ventricular fibrillation event—a life-threatening heart rhythm that can cause cardiac arrest—triggered the defibrillator component of the device implanted in Fetterman last year. The senator was evaluated at a Washington-area hospital following the incident and is now recovering, with his cardiologist indicating he should be able to return to his Senate duties after a brief period of monitoring.

Fetterman's communications director, Joe Calvello, confirmed the senator is "doing well" and doesn't anticipate any long-term effects, though he declined to specify exactly when the episode occurred. "The defibrillator did its job and kept him alive, which is exactly what it's supposed to do," said one person briefed on the medical situation who asked not to be identified discussing private health matters.

This latest cardiac event represents an escalation from Fetterman's previously disclosed atrial fibrillation, a condition that led to his 2022 stroke. The revelation that Fetterman also has cardiomyopathy—a disease of the heart muscle that weakens the organ's ability to pump blood—explains why doctors opted for a defibrillator rather than just a pacemaker when they implanted the device last year.

Cardiologists not involved in Fetterman's care note that ventricular fibrillation is considerably more dangerous than the atrial fibrillation that caused his stroke. "Atrial fibrillation increases stroke risk, but ventricular fibrillation can be immediately fatal without intervention," said Dr. Jonathan Reiner, a professor of medicine at George Washington University who reviewed the publicly available information about Fetterman's condition. "The fact that his device fired appropriately is excellent news—it means the system worked exactly as designed."

Fetterman has been transparent about his previous neglect of his health, acknowledging he went years without seeing a doctor or taking prescribed medication before his 2022 stroke. Since then, he has maintained a strict regimen of medication, diet, and exercise under his cardiologist's supervision.

Attempts to reach Fetterman's personal cardiologist for comment on Thursday were unsuccessful. A spokesperson for the George Washington University Hospital, where Fetterman has received treatment in the past, declined to confirm whether he had been admitted this week, citing patient privacy laws.

The episode comes as Congress faces several critical legislative deadlines, including government funding measures and national security packages. Fetterman's office indicated that while he may work remotely during his initial recovery period, they do not anticipate any disruption to his constituent services or committee work.

Correction: An earlier version of this article stated that Fetterman's ventricular fibrillation episode occurred on Thursday. The exact timing of the incident has not been publicly disclosed.