A crowded emergency department may be causing problems beyond the logistics of triaging and treating those patients. It may be causing new medical conditions for some patients that lead to readmission or death, researchers found.

The chaos of a crowded ED may be giving heart-attack patients symptoms of post-traumatic stress disorder, which in turn may lead to more heart attacks or other problems, according to a research letter published online by JAMA Internal Medicine.

The researchers were building on their previous meta-analysis that found that heart attack patients with PTSD symptoms one month after a heart attack had double the risk of dying or having another heart attack in one to three years.

Taking it a step further, the new research sought to find out if there was a connection between a crowded ED and getting symptoms of PTSD and found that there was, looking at 135 patients at a New York academic medical center they declined to identify.

That association increases the risk of death or another heart attack, and is a known contributor to poor quality of life, patient satisfaction and medical utilization, the authors wrote.

The next step would be to expand pool to a greater number of patients and additional hospitals. “We'd love to do more research,” said lead author Donald Edmondson, assistant professor of behavioral medicine at the Center for Behavioral Cardiovascular Health, Department of Medicine, College of Physicians and Surgeons and Columbia University Medical Center.