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Sept. 23, 2008 - Just before starting the demanding Dancing with the Stars competition, singer Toni Braxton came down with a new heart problem: microvascular angina.
It's not her first brush with heart disease. Last year, Braxton told WebMD about her 2004 brush with pericarditis -- inflammation of the tissue surrounding the heart.
People with microvascular angina, also known as cardiac syndrome X, suffer pain when doing strenuous exercise. Yet in her first appearance on Dancing with the Stars, 40-year-old Braxton was one of the top-rated dancers.
In an interview with E! News Now, Braxton said that after hearing of her new diagnosis, she planned to take a year off to let her body and mind heal. Then she changed her mind.
Is that wise? What is microvascular angina? How will it affect Braxton's performance? Her career? Her life?
WebMD consulted with top heart doctor William O'Neill, MD, executive dean for clinical affairs and professor of medicine and cardiology at the University of Miami Miller School of Medicine. We asked O'Neill:
"The term angina means chest discomfort. It is the medical term for a symptom: heart pain. It is brought about when there is a lack of blood supply to a portion of the heart muscle.
"If this happens, the person feels discomfort. People feel this differently. Nobody has exactly the same feeling with angina. Some feel it as a pressure or a burning. Most people do not feel true pain. Usually it is described as an elephant sitting on one's chest, or as if a giant hand were squeezing your chest.
"Some people don't feel it at all. People with diabetes are notorious for not feeling angina. This is called silent ischemia. The other thing that is very common is that people get very short of breath -- without pain -- as a manifestation of angina. They say, 'Doc, I feel fine, but every time I climb stairs I get really short of breath.'"
"When anything blocks blood flow to the heart, the heart has to start pumping harder, and that part of the heart becomes ischemic and you start having pain."
"In 95% of cases, lack of blood flow to the heart is due to blockages in one or more of the three main coronary arteries. Somewhere under 5% of the time, instead of major artery blockages, people have atherosclerosis in very small arteries.
"Picture the heart as the trunk of a tree. To get blood to the muscles, the tree roots branch out into smaller and smaller vessels. When these little vessels get diseased, as you exercise, you can't get enough blood to the heart."