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Rheumatic Fever And Rheumatic Heart Disease

Often recurrent, acute rheumatic fever is a systemic inflammatory disease of childhood that follows a group A betahemolytic streptococcal infection. Rheumatic heart disease refers to the cardiac manifestations of rheumatic fever, and includes pancarditis (myocarditis, pericarditis, and endocarditis) during the early acute phase, and chronic valvular disease later.

Long-term antibiotic therapy can minimize recurrence of rheumatic fever, reducing the risk of permanent cardiac damage and eventual valvular deformity. However, severe pancarditis occasionally produces fatal heart failure during the acute phase. Of the patients who survive this complication, about 20% die within 10 years.

Causes

Rheumatic fever appears to be a hypersensitivity reaction to a group A betahemolytic streptococcal infection, in which antibodies manufactured to combat streptococci react and produce characteristic lesions at specific tissue sites, especially in the heart and joints. Because very few people (about 0.3%) with streptococcal infections ever contract rheumatic fever, altered host resistance must be involved in its development or recurrence.

Although rheumatic fever tends to run in families, this may merely reflect contributing environmental factors. For example, in lower socioeconomic groups, incidence is highest in children between ages 5 and 15, probably as a result of malnutrition and crowded living conditions.

This disease strikes most often during cool, damp weather in the winter and early spring. In the United States, it's most common in the northern states.

Signs and symptoms

In 95% of patients, rheumatic fever characteristically follows a streptococcal infection that appeared a few days to 6 weeks earlier. A temperature of at least 100.4° F (38° C) occurs.

Joint pain

Most patients complain of migratory joint pain or polyarthritis. Swelling, redness, and signs of effusion usually accompany such pain, which most commonly affects the knees, ankles, elbows, or hips.

Skin lesions and nodules

In 5% of patients (generally those with carditis), rheumatic fever causes skin lesions such as erythema marginatum. This nonpruritic, macular, transient rash gives rise to red lesions with blanched centers.

Rheumatic fever may also produce firm, movable, nontender, subcutaneous nodules about 3 mm to 2 cm in diameter, usually near tendons or bony prominences of joints (especially the elbows, knuckles, wrists, and knees) and less often on the scalp and backs of the hands. These nodules persist for a few days to several weeks and, like erythema marginatum, often accompany carditis.

Chorea

Later, rheumatic fever may cause transient chorea, which develops up to 6 months after the original streptococcal infection.

Mild chorea may produce hyperirritability, a deterioration in handwriting, or an inability to concentrate. Severe chorea causes purposeless, nonrepetitive, involuntary muscle spasms; poor muscle coordination; and weakness. Chorea always resolves without residual neurologic damage.

Carditis

The most destructive effect of rheumatic fever is carditis, which develops in up to 50% of patients. It may affect the endocardium, myocardium, pericardium, or the heart valves.

Pericarditis causes a pericardial friction rub and, occasionally, pain and effusion. Myocarditis produces characteristic lesions called Aschoff's bodies (in the acute stages) and cellular swelling and fragmentation of interstitial collagen, leading to formation of a progressively fibrotic nodule and interstitial scars.

Endocarditis causes valve leaflet swelling, erosion along the lines of leaflet closure, and blood, platelet, and fibrin deposits, which form beadlike vegetations. Endocarditis affects the mitral valve most often in females; the aortic valve most often in males. In both sexes, endocarditis affects the tricuspid valves occasionally and the pulmonic valve only rarely.

Severe rheumatic carditis may cause heart failure with dyspnea, upper right quadrant pain, tachycardia, tachypnea, significant mitral and aortic murmurs, and a hacking, nonproductive cough.

The most common of such murmurs include:

• a systolic murmur of mitral insufficiency (high-pitched, blowing, holosystolic, loudest at apex, possibly radiating to the anterior axillary line)
• a midsystolic murmur caused by stiffening and swelling of the mitral leaflet
• occasionally, a diastolic murmur of aortic insufficiency. Valvular disease may eventually result in chronic valvular stenosis and insufficiency, including mitral stenosis and insufficiency and aortic insufficiency. In children, mitral insufficiency remains the major sequela of rheumatic heart disease.

Diagnosis

Recognition of one or more of the classic symptoms (carditis, polyarthritis, chorea, erythema marginatum, or subcutaneous nodules) and a detailed patient history allow diagnosis. The following laboratory data support the diagnosis:

• White blood cell count and erythrocyte sedimentation rate may be elevated (during the acute phase); blood studies show slight anemia from suppressed erythropoiesis during inflammation.
• C-reactive protein is positive (especially during the acute phase).
• Cardiac enzyme levels may be increased in severe carditis.
• Antistreptolysin O titer is elevated in 95% of patients within 2 months of onset.
• Electrocardiography changes aren't diagnostic, but the PR interval is prolonged in 20% of patients.
• Chest X-rays show normal heart size (except with myocarditis, heart failure, or pericardial effusion).
• Echocardiography helps evaluate valvular damage, chamber size, and ventricular function.
• Cardiac catheterization evaluates valvular damage and left ventricular function in severe cardiac dysfunction.

Treatment

Effective management eradicates the streptococcal infection, relieves symptoms, and prevents recurrence, reducing the chance of permanent cardiac damage.

Treatment in acute phase

During the acute phase, treatment includes penicillin or (for patients with penicillin hypersensitivity) erythromycin. Salicylates such as aspirin relieve fever and minimize joint swelling and pain; if carditis is present or salicylates fail to relieve pain and inflammation, corticosteroids may be used.

Supportive treatment requires strict bed rest for about 5 weeks during the acute phase with active carditis, followed by a progressive increase in physical activity, depending on clinical and laboratory findings and the response to treatment.

Preventive treatment

After the acute phase subsides, a monthly I.M. injection of penicillin G benzathine or daily doses of oral sulfadiazine or penicillin G may be used to prevent recurrence. Such preventive treatment usually continues for 5 to 10 years.

Surgery and other measures

Heart failure necessitates continued bed rest and diuretics. Severe mitral or aortic valvular dysfunction causing persistent heart failure requires corrective valvular surgery, including commissurotomy (separation of the adherent, thickened leaflets of the mitral valve), valvuloplasty (inflation of a balloon within a valve), or valve replacement (with a prosthetic valve). Corrective valvular surgery is rarely necessary before late adolescence.