The family of D.J. Ferguson said in a crowdfunding appeal this week that officials at Brigham and Women’s Hospital told the 31-year-old father of two that he was ineligible for the procedure because he hasn’t been vaccinated against the coronavirus.

“We are literally in a corner right now. This is extremely time sensitive,” the family said in its fundraising appeal, which has raised tens of thousands of dollars. “This is not just a political issue. People need to have a choice!”

D.J.’s mother, Tracey Ferguson, insists that her son isn’t against vaccinations, noting he’s had other immunizations in the past. But the trained nurse said Wednesday that he’s been diagnosed with atrial fibrillation — an irregular and often rapid heart rhythm — and that he has concerns about the side effects of the COVID-19 vaccine.

“D.J. is an informed patient,” Tracey Ferguson said in a brief interview at her home in Mendon, about 30 miles (48 kilometers) southwest of Boston. “He wants to be assured by his doctors that his condition would not be worse or fatal with this COVID vaccine.”