Ask the doctor: Understanding conflicting test results
Q. The results of my recent stress test indicated I may have blockages in my coronary arteries. However, when I followed up with a cardiac catheterization, my arteries looked clear. How can that be?
A. A stress test is an excellent first step when looking for heart disease. It is especially useful in people who have chest pain with activity, unexplained breathlessness, or other cardiovascular symptoms. However, no medical test is 100% accurate, and noninvasive stress tests can err in either a false negative or false positive direction.
With a false negative result, the test will not find evidence of coronary artery disease even though the heart arteries are significantly narrowed. There are many reasons a stress test might produce a false negative result. Blockages in smaller blood vessels can be missed, or certain parts of the heart muscle may be harder to assess. Therefore, if a doctor still suspects heart disease after a normal stress test, he or she may recommend another test, such as cardiac catheterization, to sort things out.