GAINSVILLE, Fla., March 7 (UPI) -- Mental stress blocks blood flow to the heart even for heart-disease patients who pass physical tests, University of Florida researchers say.
Earlier studies have linked mental stress with ischemia, or decreased blood flow, in heart disease patients who suffered chest pains during stress tests.
However, the Florida team said its study is the first to show mental stress adversely affects blood flow even for those who are symptom-free from physical exercise.
"Mental stress-induced ischemia is more common than we had recognized," said Dr. David Sheps.
He and fellow researchers reached the conclusion in a test of 29 people who were injected with a radioactive tracer while imagining they were giving a speech. Six registered ischemia symptoms even though their heart rate and blood pressure remained nearly level and none had chest pain during stress tests.
The researchers, reporting the Journal of the American College of Cardiology, said they did not know if the silent ischemia causes health problems and called for further study.