HOUSTON --Life is often a painful blur for migraine sufferers. These often debilitating headaches affect more than 29 million Americans, and treating them is often hit and miss. But a Houston teen's battle with migraines led to a startling discovery that uncovered a serious health problem she never knew she had. Samantha Duncan is a talented and gifted singer. But this High School for the Performing and Visual Arts grad had a painful secret. "I started getting migraines when I was about 10 or 11 and then I started having fainting spells when I was about 12," she said. Her migraines often forced her to miss school because the pain was so unbearable. "It was horrible, absolutely horrible," Duncan said. She spent years seeing specialists and taking a variety of medicines. "It didn't get rid of the migraines. Only time would," Duncan said. She found the source of her problem when her mother took her to see Dr. Mohammed Numan at UT Health Children's Memorial Hospital. "When he heard about her history of migraines, he said, 'We oughta check you. You may have a heart defect,'" said Paula Vadervoort, Duncan's mother. "I see about three to four patients per week with the same complaints," Dr. Numan said. Duncan had a defect that causes holes in the heart called atrial septal defect. Dr. Numan scheduled her for surgery, but before he did, he asked her mother one important question. "He turned to me and said, 'Do you have migraines? And I said, 'I have crippling migraines that I've had since I was 12,'" Vandervoort said. It turned out she had the same problem. Mom and daughter had their heart surgeries about two months apart. The procedure was minimally invasive and both returned quickly to their routines. But did it work? "I was having headaches every day, migraines several times a month and now, I'm pretty much headache, pain, migraine-free. It's amazing," Duncan said. "I haven't had a migraine since," Vandervoort said. "But no one had ever mentioned that it was possible that a heart defect could be causing it." But she's thankful because the discovery changed two lives. Dr. Numan says about 70 percent of his patients have seen their migraines end because of the surgery. About 10 percent don't see any improvement at all, but he's convinced that it works.