Rheumatic Heart Disease: How an Untreated Sore Throat Can Damage Heart Valves

Introduction

Of all the heart conditions a surgeon operates on, rheumatic heart disease is the most frustrating — because it was preventable. It begins not in the heart but in the throat, with a common bacterial infection that is cheap and simple to treat. Left untreated, it can set off an immune reaction that quietly destroys heart valves over years, so that a patient in their twenties or thirties needs valve surgery.

In many high-income countries it has become rare. Across much of the world, including our region, it remains a leading cause of valve disease in young people. That gap is not genetic. It is a gap in treating sore throats.

The chain of events

1. The infection

It starts with pharyngitis caused by group A Streptococcus — strep throat. Most sore throats are viral and need no antibiotic. Streptococcal throat infection is different, and it is the one that matters here.

2. The immune system attacks the wrong target

The body makes antibodies against the bacterium. The problem is that certain proteins on the streptococcus closely resemble proteins in human tissue — particularly in heart valves, joints, skin and brain. In susceptible people, the immune response cross-reacts and begins attacking the body's own tissue. This is called molecular mimicry. The bacteria may be long gone; the immune reaction continues.

3. Acute rheumatic fever

Typically two to four weeks after the throat infection, acute rheumatic fever may appear: fever, painful swollen joints that characteristically move from one joint to another, fatigue, sometimes a rash, nodules under the skin, or involuntary jerky movements (Sydenham chorea). The joints hurt but recover completely. The heart does not. The old teaching still holds — rheumatic fever "licks the joints but bites the heart".

4. Chronic rheumatic heart disease

Each episode inflames and scars the valves. Scarring makes leaflets thicken, fuse at their edges, and shorten. Over years this produces a narrowed valve (stenosis), a leaking valve (regurgitation), or both. The mitral valve is affected most often, followed by the aortic valve.

Why it is often silent for years

The damage accumulates slowly, and the heart compensates. Many patients have no symptoms through adolescence and present later with:

  • breathlessness on exertion, then at rest or lying flat;
  • fatigue and reduced exercise tolerance;
  • palpitations — atrial fibrillation is common once the left atrium enlarges;
  • swelling of the legs or abdomen;
  • in mitral stenosis, sometimes coughing blood.

A particular danger is pregnancy. The extra circulating volume can unmask previously silent mitral stenosis, and a woman who felt well may deteriorate sharply in the second or third trimester.

Diagnosis

A murmur on examination is often the first clue. Echocardiography confirms the diagnosis, identifies which valves are involved, grades severity, and measures the consequences on chamber size and pulmonary pressures. ECG may show atrial fibrillation or chamber enlargement. In acute rheumatic fever, evidence of preceding streptococcal infection and inflammatory markers support the diagnosis against established clinical criteria.

Treatment

Preventing further damage

This is the part most often neglected. After rheumatic fever, long-term antibiotic prophylaxis — usually long-acting penicillin injections at regular intervals — prevents repeat streptococcal infections and further valve damage. It continues for years, and the duration depends on age and whether the heart is already involved. Stopping early because the patient feels well is a common and costly mistake.

Treating the damaged valve

  • Medication controls symptoms and complications — heart failure treatment, rate control for atrial fibrillation, and anticoagulation where indicated — but it does not repair the valve.
  • Balloon valvuloplasty can open a narrowed mitral valve in selected patients whose valve anatomy is favourable and who have no significant leakage or clot.
  • Surgical repair is preferred where the valve is repairable, since it preserves the patient's own tissue and usually avoids lifelong anticoagulation.
  • Valve replacement is needed when the valve is too scarred and calcified to repair. The choice between a mechanical and a tissue valve is especially important here, because these patients are young — it involves durability, anticoagulation, and plans for pregnancy.

Prevention: where the chain breaks

Every link above can be broken at the first one.

  • Take a child's sore throat seriously when it comes with fever, painful swallowing, swollen tender neck glands, and no cough — the pattern that suggests bacterial rather than viral infection. A throat swab or rapid test settles it where available.
  • Complete the antibiotic course. Symptoms improve in days; the course exists to eradicate the organism, not to relieve the sore throat.
  • Seek review if joint pains or fever follow a throat infection by a few weeks.
  • Continue prophylaxis exactly as prescribed after a confirmed episode of rheumatic fever.
  • Maintain dental hygiene — damaged valves are vulnerable to endocarditis.

Key points

  • Rheumatic heart disease begins with a treatable streptococcal throat infection.
  • The damage is caused by the immune response, not by bacteria in the heart.
  • The mitral valve is the most commonly affected.
  • It is usually silent for years and may first appear in pregnancy.
  • Penicillin prophylaxis after rheumatic fever prevents progression — and stopping it early is a frequent cause of avoidable valve surgery.

This article is general health education, not advice about your own case. If you or your child has a sore throat with fever, or you have been told you have a heart murmur or rheumatic heart disease, seek medical assessment. Do not start or stop antibiotics without medical advice.