Rheumatic heart disease is permanent damage to the heart valves caused by the body’s own immune system after one or more episodes of rheumatic fever. It affects over 40 million people worldwide and causes roughly 310,000 deaths each year. The condition begins with something as common as strep throat, and it can take years or even decades before the heart damage produces noticeable symptoms.
How Strep Throat Leads to Heart Damage
The chain of events starts with a throat infection caused by group A streptococcus bacteria. Most strep throat infections clear up without lasting harm, especially when treated with antibiotics. But in a small percentage of cases, the immune system’s response to the bacteria goes off course. Immune cells that were activated to fight the strep infection begin producing antibodies that mistakenly attack the body’s own tissues, particularly the heart valves. This misdirected immune attack is called rheumatic fever.
Rheumatic fever can inflame the heart, joints, skin, and nervous system. It is the heart inflammation, called carditis, that poses the greatest long-term risk. During an episode of rheumatic fever, immune cells infiltrate the valve tissue. Over time, especially with repeated episodes, this inflammation causes the valve leaflets to thicken, scar, and stiffen. The result is valves that either fail to open properly (stenosis) or fail to close completely (regurgitation), or both. The mitral valve, which sits between the left atrium and left ventricle, is the most commonly affected.
Who Is Most at Risk
Rheumatic heart disease disproportionately affects people in low- and middle-income countries where access to healthcare is limited and strep throat infections go untreated. Overcrowding, poverty, and lack of antibiotics are the main drivers. Children between 5 and 15 are most vulnerable to rheumatic fever, though the resulting heart damage often doesn’t become apparent until adulthood. In high-income countries, the disease has become rare thanks to widespread antibiotic use, but it persists in Indigenous communities in Australia, New Zealand, and parts of North America where healthcare disparities remain.
Symptoms and How It’s Found
One of the tricky things about rheumatic heart disease is that it often produces no symptoms for years. Some people develop signs of heart involvement during an acute episode of rheumatic fever, but in many cases, symptoms don’t appear until the valve damage has progressed significantly. When they do show up, common symptoms include:
- Shortness of breath during exercise, at rest, or while lying flat
- Fatigue that limits daily activity
- Chest pain
- Heart palpitations or irregular heartbeat, including atrial fibrillation
- Swelling in the feet, hands, or abdomen
- Coughing up blood in advanced cases
A heart murmur, an unusual sound heard through a stethoscope, is often the first clinical sign. But not all rheumatic heart disease produces an audible murmur. Echocardiography (an ultrasound of the heart) is the gold standard for diagnosis. It can reveal thickened valve leaflets, restricted leaflet motion, and abnormal blood flow patterns even before symptoms develop. The World Heart Federation has established specific echocardiographic criteria that classify findings into “definite” and “borderline” rheumatic heart disease, which is particularly useful in screening programs targeting children in high-risk regions. Disease detected on echo without an audible murmur is referred to as subclinical rheumatic heart disease.
Complications of Advanced Disease
As valve damage worsens, the heart has to work harder to pump blood. Over years, this extra strain leads to heart failure, where the heart can no longer meet the body’s demands. The scarred, narrowed valves also disrupt normal blood flow patterns inside the heart, which promotes blood clot formation. These clots can travel to the brain and cause stroke. Atrial fibrillation, a type of irregular heartbeat, is common in advanced disease and further increases stroke risk.
Damaged valves are also vulnerable to infection. Bacteria circulating in the bloodstream can settle on scarred or prosthetic valves, causing a serious condition called infective endocarditis. This can trigger a cascade of problems including kidney failure, liver dysfunction, and additional strokes. Infective endocarditis on top of existing rheumatic heart disease is a life-threatening emergency.
Prevention: The Most Effective Strategy
The single most effective way to prevent rheumatic heart disease is to treat strep throat with antibiotics before the immune system has a chance to trigger rheumatic fever. A single injection of long-acting penicillin or a 10-day course of oral penicillin can eradicate the strep bacteria and prevent rheumatic fever from developing in the first place. This is called primary prevention, and it is the reason rheumatic heart disease has nearly disappeared in wealthier nations.
For people who have already had rheumatic fever, the priority shifts to preventing recurrences, because each new episode of rheumatic fever adds more damage to the heart valves. This secondary prevention involves regular penicillin injections, typically given every 3 to 4 weeks. The duration depends on the severity of heart involvement:
- Rheumatic fever without heart involvement: prophylaxis for 5 years or until age 21, whichever is longer
- Rheumatic fever with heart inflammation but no lasting valve damage: 10 years after the last episode, or until age 21
- Rheumatic fever with persistent valve disease: at least 10 years and until age 40, sometimes lifelong
- Severe valve disease or after valve surgery: lifelong
Adherence to these injections is one of the biggest challenges in managing rheumatic heart disease globally. The injections are painful, must be given regularly for years, and require consistent access to healthcare. Many people in the highest-risk communities struggle to maintain the schedule.
Treatment for Established Valve Damage
Once the valves are permanently damaged, treatment focuses on managing symptoms and preventing complications. Medications can help control heart failure symptoms, regulate heart rhythm, and reduce the risk of blood clots. But when valve damage is severe enough to cause significant symptoms or strain on the heart, surgery becomes necessary.
Mechanical valve replacement has long been the standard surgical approach. It reliably eliminates the stenosis or regurgitation in the short term, but it comes with a major trade-off: mechanical valves require lifelong blood-thinning medication to prevent clots from forming on the artificial valve. This is a particular burden in low-resource settings where regular blood monitoring and a reliable supply of anticoagulant medication may not be available.
Valve repair, which reshapes the patient’s own valve tissue rather than replacing it, is an alternative that avoids the need for lifelong blood thinners. Repair works best in younger patients with isolated valve leaking or mild to moderate narrowing. Older patients and those with heavily scarred, calcified valves tend to have less durable results. When the aortic valve is severely narrowed, repair has not consistently outperformed replacement with a biological valve prosthesis.
The global burden of rheumatic heart disease has been declining in terms of death rates, with mortality dropping steadily since 1990. But the total number of people living with the condition continues to rise as populations grow in affected regions. The gap between what is preventable with a simple course of antibiotics and what actually happens in communities without reliable healthcare access remains one of the starkest inequities in global health.