What happened to a close relative of mine (let's call her Lucy) prompts me to urge anyone who had rheumatic fever as a child to seek an evaluation by a cardiologist.

Lucy was in her mid-50s and feeling fine. One morning, while working at her job as a bank teller, she collapsed and couldn't be roused. She was taken to a hospital where doctors quickly diagnosed a massive stroke from an embolus (blood clot).

When they examined her heart, the doctors found the typical signs of mitral stenosis, an obstruction to the flow of blood into the left ventricle, which pumps blood to all of the body except the lungs. Family members then revealed that Lucy had had a bout of rheumatic fever as a child. Her stroke was fatal.

Rheumatic fever is caused by a strep-throat infection. The body defends itself from the streptococcal bacteria by producing antibodies that may lead to an episode of rheumatic fever, with symptoms of joint pain, fever, and heart murmurs. The antibodies remain in the body after rheumatic fever and over a period of years, they can progressively damage the valves in the heart. Thickening of the mitral valve is a particular risk because, as the damage continues, the thickened valve can produce mitral stenosis.

Shortness of breath on exertion is the most prominent symptom of mitral stenosis but, like Lucy, many people with mitral stenosis have no symptoms for many years. A stroke from a blood clot in the left atrium is the first manifestation of the disorder in nearly a quarter of those with mitral stenosis.

The obstruction of blood flow from the left atrium results in enlargement of the atrium, stagnation of blood with a tendency for clot formation, and, in about half of the people affected, the development of atrial fibrillation.

Lucy's fatal stroke might have been prevented if doctors had detected and treated her mitral stenosis. If you or someone you know has a history of rheumatic fever, I recommend an examination by a cardiologist because the heart murmurs and other abnormal heart sounds caused by mitral stenosis may be subtle enough to be missed by a less experienced doctor.