My husband recently had a mitral valve replaced and is worried about strep infections. He gets sore throats fairly frequently, with white spots. Could this have any connection to his heart problems?

P.F.

The heart contains four valves, which separate the organ's four chambers and permit blood to flow only in the correct direction. Many conditions can damage one or more heart valves, and sometimes the damage is so great that a valve needs to be surgically replaced. Nowadays, more and more people are having this operation.

Heart-valve infection (endocarditis) can occur in people with normal heart valves, but the risk is much greater for people who have damaged valves or mechanical replacements. Endocarditis may further harm an already damaged valve, so much so that the heart may not be able to function correctly. The infection can also cause severe problems outside the heart. Bacteria can spread through the bloodstream and damage other organs. Without treatment, such a patient will die. With treatment, however, the patient has a good chance of recovery.

Certain bacteria are prone to infecting the heart valves. The most common are from the Streptococcus (strep) family, particularly a group of bacteria that are normally found around the teeth. These are not the same type that cause strep throat infections, which are rarely a cause of endocarditis. People with damaged or mechanical valves must take antibiotics when they have a dental procedure, because antibiotics can minimize the risk of bacteria from around the teeth getting into the bloodstream, sticking to the valve and causing endocarditis.

So, to answer your question, sore throat -- even strep throat -- does not put your husband at especially high risk of endocarditis. I doubt that his sore throat is related to his heart problems at all.

One possibility, however, could link your husband's valve trouble and sore throat -- the disease called rheumatic fever. Rheumatic fever occurs in some people, usually children, who get strep throat. For reasons not entirely understood, the throat infection causes the body's disease-fighting immune system to attack the heart valves, usually the mitral valve. In addition to the heart trouble, people with rheumatic fever have joint problems, a skin rash and skin bumps called nodules. People who have rheumatic fever in childhood may not be aware of the damage to the valve until middle age. It is then that the patient may need to have a valve replaced.

Rheumatic fever is a relatively severe illness, and it would be unusual for a person with this disease to have just a minor sore throat without other symptoms. Also, the disease is quite unusual in the United States, especially in adults, though it is common in the developing world. Rheumatic fever was common in the United States before the 1960s, however, when your husband may have been a child.

Since rheumatic fever is a possibility, albeit an unlikely one, your husband should ask his doctor if his illness could be related to it. If not, he should find out the underlying cause of his mitral-valve disease.