Heart disease is the leading killer of women, and its onset can be more subtle in females, experts say.

“Our symptoms tend to be a lot more vague,” said Amy Burke, program manager of the Dean Ornish Program for Reversing Heart Disease at Windber Medical Center.

“Sometimes they just are not feeling well,” Burke said. “They might have a pain in the back between the shoulder blades.”

Many believe women and men with heart disease risk factors should have preventive stress-test screenings to determine whether their heart function is compromised.

“Women should have routine cardio-exams just like they have a breast exam,” Dr. Catherine Comas of Windber said.

A cardiac stress test can detect abnormal blood flow in the heart, which often indicates a restricted blood vessel. A severe reduction in blood supply causes a heart attack.

Comas explained the steps of a stress test, which must be ordered by a physician.

A patient is injected with a mild radioactive isotope and spends several minutes walking on a treadmill. Sensors record and report heart rate and other vital signs until the patient reaches the target heart rate, based on age and physical condition.

From the treadmill, patients go to the X-ray department where images show blood flow through vessels supplying the heart muscle. A second set of “resting” images taken a few hours later help doctors see changes in blood flow at higher volumes.

Nuclear technician Ann Coleman compared the heart’s blood vessels to an urban traffic system.

“Your heart consists of three four-lane highways,” Coleman said.

“If somebody shuts down two lanes at rush hour, you can’t get through.”

Like a traffic jam, the X-ray would show a backup of blood behind the restriction on the after-treadmill image. It would look very different on the resting test, Coleman said.

“The same image on the resting test is like hitting the two-lane section at 3 p.m.,” she said. “It looks like there is no problem.”

Once an abnormality is detected, a doctor might order more testing, or advise a patient to start healthy diet and exercise, with regular testing, exams and follow-up care.

A cardiac catheterization usually is the next test. That’s when a small plastic tube is fed through blood vessels to the heart to measure blood flow, oxygen levels and pumping ability.

Comas recommended baseline stress tests for anyone at risk for heart disease. Risk factors include diabetes, obesity, high blood pressure and family history. Although some doctors like to wait until someone has symptoms of heart problems before suggesting the test, Comas warned it can be too late by then.

“For 25 percent of people with heart disease, the first symptom is sudden coronary death,” she said. “They are hitting the floor with a heart attack.”

Several factors put women more at risk for serious heart disease, Coleman said.

Many women follow advice on breast-cancer screening but neglect heart disease screenings because they have heard the female hormone estrogen protects women. But that protection goes down as the body’s production of estrogen drops after menopause, Coleman warned.

Then there are the differences in symptoms.

“Women don’t traditionally get the clutching chest pain men do,” Coleman said. Shortness of breath, jaw pain, arm pain and back pain are typical indicators of heart events in women.

Coleman said many women are used to enduring discomfort as they focus on caring for families. They often ignore the symptoms of heart disease.

“Women’s heart attacks tend to be more severe because they don’t seek medical attention as soon,” Coleman said.

That’s why the Windber Medical Center team is working to raise awareness among women, Coleman said. All post-menopausal women should talk to their doctors about heart disease, she said.

“The kids are in college, and they have a breather,” she said. “They really owe it to themselves to go into their doctor and say, ‘I really want one of these (stress) tests.’ ”