Lori Kupetz looks younger than her 40 years, especially when she hula-hoops in front of her Sherman Oaks home with daughters Sophie, 9, and Zoe, 7. No one would ever guess that earlier this year, this thin vegetarian who doesn’t smoke underwent a triple bypass.

“I just don’t fit the bill of someone who would have heart surgery,” says Kupetz, who is now out to spread the word about cardiovascular disease from a female perspective. “But heart disease kills women more than anything else. It’s not just a man’s disease.”

And sadly, for many women, it often goes unnoticed.

“It’s very tragic, but unfortunately two-thirds of women will actually die of heart disease and not know they have a problem,” says Dr. Lisa Matzer, medical director of Glendale Adventist Medical Center’s Outpatient Cardiac Services Program.

Doctors and researchers say this is partly because heart disease affects men and women differently.

“The symptoms women present are a lot different than the symptoms we typically see in men,” says Matzer. She says the most common for women include weakness, fatigue, shortness of breath with exercise and just not feeling right.

In addition, tests that work for men aren’t always as effective for women.

“Making the diagnosis of heart disease can be difficult,” Matzer says. “The angiogram is the gold standard for men, so we assume it’s the gold standard for women. But it only works for one-third of women. We know that two-thirds of women (with heart problems) will go in and be given a clean bill of health.”

For Kupetz, too, getting the right diagnosis proved elusive.

Her story began in February 2005. One day while hiking with a friend, she found herself doubled over with chest pains. After two more similar episodes, she called her internist. In light of her family history of heart attacks combined with her own high cholesterol level, he recommended she see a cardiologist.

“ ‘Doctor, I’m having the pains right now,’ ” Kupetz said in the cardiologist’s office, while taking a standard stress test on a treadmill.

But he couldn’t see any abnormalities, so he diagnosed her chest pains as non-cardiac-related and sent her to a gastroenterologist. The pattern continued.

Nearly one year, four doctors and seven major tests later, Kupetz didn’t have answers. And she was still getting chest pains from everyday activities like dancing with her kids or bringing in groceries. She had stopped exercising. One doctor suggested she take antidepressants.

Matzer hears this a lot. “You go into my waiting room and ask who has a Valium and they all raise their hands because they’ve been told they have a psychological problem. But it’s not all in their head. It’s all in their heart.”

Kupetz finally found answers when she called Dr. C. Noel Bairey Merz, medical director of the Women’s Health Program, Preventive and Rehabilitative Cardiac Center, at Cedars-Sinai Medical Center in Los Angeles.

Confident that Kupetz did indeed have a heart problem after hearing her story, Bairey Merz ordered an echocardiac stress test and an adenosine cardiac stress MRI. Both showed that Kupetz’s heart was not responding as it should.

A subsequent angiogram found three arteries with major blockages. After an attempt at angioplasty, Kupetz had triple-bypass surgery in March. Through it all, her family, especially Daniel, her husband of 12 years, was by her side. Kupetz credits Bairey Merz with saving her life, but the doctor says Kupetz deserves praise, too.

“Lori was a positive advocate for herself. She didn’t stop pursuing it or ignore her symptoms. Doctors can only do so much. They need active partners in the process.”

Bairey Merz continues to keep track of her patient’s health and Kupetz does her part by maintaining a regimen of statin drugs, beta blockers, aspirin and prescribed doses of fish oil.

Kupetz’s pain, triggered by insufficient blood flow to her heart, is finally gone. The only visible sign now is a scar on her collarbone. Recently while she was getting dressed, her daughter protested when she tried to hide it with a high collar.

“Every scar has a story,” her daughter told her. “And you should be proud of yours.”