Coronary artery disease may take a different course in men and women, which may explain why the rate of death for women has declined more slowly than for men, according to the October issue of Mayo Clinic Health Letter.

Several landmark studies published in the last year indicate that more women than men suffer from microvascular, or small vessel, heart disease, where the heart’s tiniest vessels become clogged or narrowed, limiting blood supply to the heart.

These tiny clogged vessels don’t show up on standard diagnostic tests, and doctors may assume that symptoms such as fatigue, light-headedness, or chest, neck or shoulder pain are caused by something other than heart disease. Yet, for some patients - more often women - these symptoms can develop into recurrent chest pain, a heart attack or heart failure.

Mayo Clinic doctors recommend additional testing for people with coronary artery disease symptoms and no indication of clogged arteries on a coronary angiogram - the diagnostic tool for visualizing narrowing or blockage in the large coronary arteries.

Additional tests include positron emission tomography (PET), a noninvasive imaging test that can suggest, but not diagnose, microvascular disease. The gold standard test for microvascular disease is an endothelial dysfunction test, a special type of coronary angiogram. It involves placing a tiny wire called a Doppler wire inside a coronary artery and measuring blood flow.

Research on microvascular disease continues. Until more is known, be aware of heart disease symptoms. Seek diagnosis and treatment when symptoms occur and talk to your doctor about testing for microvascular disease.