Heart Disease - Rheumatic fever and rheumatic heart disease



Rheumatic heart disease is the possible sequel of rheumatic fever and claims the lives of 13,000 annually. It generally strikes children between the ages of 5 and 15. All told, 1.6 million persons are suffering from rheumatic heart disease, with about 100,000 new cases reported each year. Triggered by streptococcal attacks in childhood and adolescence, rheumatic fever may leave permanent heart scars. The heart structures most often affected are the valves.

Causes

The cause of rheumatic fever is still not entirely understood. It is known that rheumatic fever is always preceded by an invasion of bacteria belonging to the group A beta hemolytic streptococcus family. Sooner or later, everybody has a strep infection, such as a strep throat. Most of us get over it without any complications. But in 1 out of every 100 children the strep infection produces rheumatic fever a few weeks later, even after the strep attack has long since subsided. The figure may rise to 3 per 100 during epidemics in closed communities, such as a children's camp.

The invasion of strep sparks the production of protective agents called antibodies. For some reason, in a kind of biological double cross, the antibodies attack not only the strep but also make war on the body's own tissues—the very tissues they are called upon to protect. Researchers are now suggesting the possible reason, although all the evidence is not yet in. According to a widely held theory, the strep germ possesses constituents ( antigens ) that are similar in structure to components of normal, healthy cartilage and connective tissues—found abundantly in joints, tendons and heart valves—in susceptible individuals. Failing to distinguish between them, the antibodies attack both. The result: rheumatic fever involving joint and valve inflammation and, perhaps, permanent scarring.

Symptoms

Rheumatic fever itself is not always easy to diagnose. The physician must detect at least two of the following major symptoms or one major and two minor symptoms, derived by the American Heart Association.

Major:

  1. • Swelling or tenderness in one or more joints (arthritis); usually, several joints are involved one after the other in migratory fashion
  2. • Carditis or heart inflammation
  3. • An unusual raised skin rash, which often disappears in 24 to 48 hours
  4. • Chorea, or St. Vitus's dance, so-called because of the uncoordinated, jerky and involuntary motions of the arms, legs, or face, which result from rheumatic inflammation of brain tissue; (it may last six to eight weeks and even longer, but when symptoms disappear there is never any permanent damage and the brain and nervous system return to normal)
  5. • Hard lumps, under the skin and over the inflamed joints, usually indicating severe heart inflammation

Minor:

  1. • Joint aches without inflammation
  2. • Fever
  3. • Previous rheumatic fever or evidence of rheumatic heart disease
  4. • Abnormal heartbeat on EKG
  5. • Blood test indicating inflammation

Confirmation of rheumatic fever also requires other clinical and laboratory tests, to determine, for example, the presence of strep antibodies in the patient's blood. Rheumatic fever does not always involve the heart; even when it does, permanent damage is not inevitable. Nor does the severity of the attack have any relationship to the development of rheumatic heart disease.

The real danger arises when heart valve tissue becomes inflamed, affecting the valve's ability to close properly. When the acute attack has passed and the inflammation finally subsides, the valves begin to heal, with scar tissue forming.

Scar tissue may cause portions of the affected valve leaflets to fuse together. ( Leaflets are the flaps of the heart valves.) This restricts leaflet motion, impeding the full swing action and thereby blood flow through the valve. This condition is called valvular stenosis . The leaflets may become shrunken or deformed by healing tissue, causing regurgitation or backspill because the valve fails to close completely.

Both stenosis and regurgitation are often present. Most susceptible are the mitral valve , which regulates flow from the upper to the lower left chambers of the heart, and the aortic valve , the gateway between the left ventricle and the general circulation. Rarely attacked are the two valves in the right chambers.

Treatment

During the acute stages of rheumatic fever, the patient is given heavy doses of antibiotics to rid the body of all strep traces, aspirin to control swelling and fever, and sometimes such hormones as ACTH and cortisone to reduce inflammation.

In the past, rheumatic fever spelled mandatory bed rest for months. Now the routine is to get the patient up and about as soon as the acute episode is over to avert the problem of psychological invalidism. The biggest restriction, especially for young people, is that no participation in competitive sports or other severely taxing exercises is allowed for two to three months while a close watch is kept on cardiac status.

The patient with valve damage can in many cases be treated medically, without the need for surgical intervention. He may, of course, have to desist from certain strenuous activities, but in all other ways he can lead a relatively normal life. Surgical relief or cure is available, however, for patients with severe damage or those who may, with age, develop progressive narrowing or leakage of the valves.

Surgery

Stenotic valves can be scraped clear of excess scar tissues, thereby returning the leaflets to more normal operation. In some cases individually scarred leaflets are replaced with synthetic substitutes. The correction of severe valvular regurgitation requires replacement of the entire valve with an artificial substitute, or, as some surgeons prefer, with a healthy valve taken from a human donor dying of other causes.

Prevention

The development of antibiotics has made rheumatic fever preventable. These drugs can knock out the strep before the germs get a chance to set off the inflammatory defense network sequences, but early detection is necessary. Among the symptoms of strep are a sore throat that comes on suddenly, with redness and swelling; rapidly acquired high fever; nausea and headaches. The only sure way to tell, however, is to have a throat swab taken by passing a sterile piece of cotton over the inflamed area. This culture is then exposed for 24 hours to a laboratory dish containing a substance that enhances strep growth. A positive identification calls for prompt treatment to kill the germs before the complications of rheumatic fever have a chance to set in.

Unfortunately, many strep infections may be mild enough to escape detection. The child may recover so quickly that the parents neglect to take the necessary precautions, but the insidious processes may still be going on in the apparently healthy child. This is a major reason why rheumatic fever is still with us, though in severe decline.

Heart Murmurs and Recurrences of Rheumatic Fever

The prime sign that rheumatic heart disease has developed is a heart murmur—although a heart murmur does not always mean heart disease. The murmur may be only temporary, ceasing once the rheumatic fever attack subsides and the stretched and swollen valves return to normal. To complicate matters more, many heart murmurs are harmless. Such functional murmurs may appear in 30 to 50 percent of normal children at one time or another.

As many as three in five patients with rheumatic fever may develop murmurs characteristic of scarred valves—sounds of blood flowing through ailing valves that fail to open and close normally.

Anyone who has had an attack of rheumatic fever has about a 50-50 chance of having one again unless safeguards are taken. As a result, all patients are placed on a daily or monthly regimen of antibiotics. The preventive dose, although smaller than that given to quell an in-progress infection, is enough to sabotage any attempts on the part of the strep germs to mount an attack.

There is some encouraging evidence that rheumatic fever patients who escape heart damage the first time around will do so again should a repeat attack occur. On the other hand, those with damaged valves will probably sustain more damage with subsequent strep-initiated attacks.

Endocarditis

One of the additional bonuses of antibiotic therapy is that it has all but eliminated an invariably fatal complication to which rheumatic patients were especially vulnerable—an infection of the heart's inner lining, or endocardium , called subacute bacterial endocarditis . The scar tissue provides an excellent nesting site for bacteria to grow.

The responsible germs are found in most everyone's mouth and usually invade the bloodstream after dental surgery. Fortunately, it is easy to prevent or cure because the germs offer little resistance to antibiotics. As a precaution, dentists are usually advised to give rheumatic fever patients larger doses of penicillin (or other antibiotics to those allergic to penicillin) before, during, and after dental work.



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