Cardiologists at North Carolina Children’s Hospital had worried for several years that children with complex conditions were dying at higher-than-expected rates. By 2016, it seemed that even patients undergoing lower-risk heart surgeries were suffering more complications. In meetings in 2016 and 2017, captured on secret recordings provided to The New York Times, doctors urged their bosses to take action.

The hospital, part of the University of North Carolina health system, defends its pediatric heart surgery program. UNC administrators described it as “very strong” today and denied any past problems affecting patient care. They told The Times there was “a dysfunctional group” in 2016 that sowed mistrust, creating “team culture issues,” and noted that today there are “new team members.” A Times investigation found that as the doctors were weighing their ethical obligations to patients, hospital leaders also worried about harming the surgical program.

Some cardiologists wondered whether they should stop referring patients to surgeons inside their own hospital