Half of all heart attack survivors experience memory loss, attention problems, and other cognitive deficits, new research shows.

The study, led by Lund University investigators, suggests cardiac arrest causes a temporary lack of oxygen to the brain that has lasting effects on patients' mental functions that could lead to dementia.

The findings are based on the experiences of 950 heart attack survivors in Europe and Australia who underwent cognitive screening tests. Both the patients and their relatives were also asked to report changes that had taken place following the cardiac arrest.

Tobias Cronberg, M.D., associate professor at Lund University and consultant neurologist at Skåne University Hospital, said the study underscores the need to provide quality post-operative care — such as encouraging healthy lifestyle habits that boost brain function — to compensate for the potential cognitive deficits that heart attack patients may suffer.

"Our conclusion is that if we are to provide good treatment to cardiac arrest patients, we don't just need to save their lives; we also need to ensure that they tackle these risk factors, for example through improved diet and more exercise. Otherwise they are at risk of developing dementia," said Dr. Cronberg, who reported the team’s findings in the journals Circulation and JAMA Neurology.