What is Rheumatic Heart Disease?
Rheumatic heart disease is a condition where the body’s immune system begins to attack itself after an infection in the throat caused by a type of bacteria known as beta-hemolytic streptococci. This disease is primarily found in developing countries. Each year, it claims the lives of 250,000 young people around the world. Additionally, over 15 million individuals have signs showing they might be suffering from rheumatic heart disease.
What Causes Rheumatic Heart Disease?
Rheumatic heart disease happens when rheumatic fever, a type of illness that can follow a strep throat infection, strikes the heart repeatedly, or even just once. It makes parts of the heart, like the flaps that control blood flow (valve cusps), stiffer and misshapen. The fever can also cause these flaps to stick together (fusion of the commissures), or shorten and stick together the tiny tendons that connect our heart muscles to the heart flaps (chorade tendinae). This can take 20 to 30 years to lead to narrowed or leaky heart valves (valvular stenosis and/or regurgitation).
Typically, in chronic rheumatic heart disease, the mitral valve, one of the valves in the heart, is affected in about 50% to 60% of all cases. In 20% of cases, both the mitral and another valve, called the aortic valve, are affected. The tricuspid valve, yet another heart valve, is affected in about 10%. But, this usually happens only when the mitral or aortic valve has also been affected and there have been repeated infections. It’s quite rare for the last of the heart’s valves, the pulmonary valve, to be affected by this disease.
Risk Factors and Frequency for Rheumatic Heart Disease
Rheumatic heart disease (RHD) is a serious type of heart disease that often affects children and young adults in developing areas. It is mainly seen in people who live in poverty, have limited healthcare access, and are regularly exposed to a specific type of bacteria, namely group A streptococcus. It’s estimated that much of the disease burden could be due to undiagnosed RHD, which is often harder to detect because it doesn’t show obvious symptoms.
- RHD is responsible for about 15 to 20 percent of all heart failure patients in regions where the disease is common.
- A research study in 2015 found that there were around 33.4 million global cases of RHD, 10.5 million cases of lost healthy life years due to RHD, and 319,400 deaths from RHD.
- The same study noted the highest rates of RHD in Oceania, central sub-Saharan Africa, and South Asia, with incidence rates as high as 444 cases per 100,000 people in endemic regions.
- In contrast, there were only 3.4 cases per 100,000 people in non-endemic regions.
- “Silent” RHD, which shows no obvious symptoms, is around seven to eight times more common than noticeable RHD, with rates of 21.1 versus 2.7 people per 1000, respectively.
- The number of people with RHD tends to grow with age, and can range from 4.7 per 1000 five-year-old children to 21.0 per 1000 sixteen-year-old children.
- Some calculations based on these figures suggest that there could currently be between 50 to 80 million people affected by RHD worldwide.
Signs and Symptoms of Rheumatic Heart Disease
Rheumatic fever is a major cause of heart disease that affects children and young adults around the world. It usually occurs a couple of weeks following an infection in the throat caused by a specific type of bacteria known as group A beta-hemolytic streptococcal.
The most severe symptom of rheumatic fever is Carditis – an inflammation of the heart. This can affect different areas of the heart, such as the outer layer (pericardium), the muscular wall (myocardium), and the heart valves. Depending on which part of the heart is affected, the results can be different:
- If you hear a distinctive, scratching sound under a stethoscope, it might indicate that the outer layer of the heart is inflamed (pericarditis).
- If there are symptoms of heart failure like swelling in the lower limbs, shortness of breath while resting or exerting, bloating, or difficulty lying flat due to breathlessness, it might point to an inflamed heart muscle (myocarditis).
However, if a person has heart inflammation but no problems with their heart valves, it’s not likely to be due to rheumatic fever. Therefore, a physical examination is necessary to listen for certain heart sounds (murmurs) which may indicate an issue with heart valves. Mitral regurgitation – a leakage of the mitral valve – is the most commonly occurring problem and it can be identified on examination as a certain type of murmur. Less common is a condition called Aortic regurgitation.
For patients known to have rheumatic heart disease, any change in their heart murmurs or a new murmur can suggest that they have acute rheumatic heart fever. This condition majorly affects the heart valves on the left side. The tricuspid valve and very rarely the pulmonary valve on the right side may also be affected, but it is highly unlikely unless there is a problem with the mitral valve.
Testing for Rheumatic Heart Disease
Rheumatic heart disease can lead to a variety of heart issues, such as inflammation of the heart muscle (myocarditis), weakened heart that results in an accumulation of excess fluid in the body (congestive heart failure), disturbances in the heartbeat rhythms (arrhythmias), and diseases affecting the heart valves (valvular heart disease).
If a doctor suspects myocarditis, they might check for changes in your heart’s electrical activity using an electrocardiogram (EKG). This test can show various forms of ‘heart block,’ which can interrupt or slow down the signals that control the heart beat.
A chest X-ray could also be done to look for a large heart (cardiomegaly) or congestion in the blood vessels of the lungs, which can point to congestive heart failure.
A more sensitive and specific test for finding rheumatic heart disease is called a transthoracic echocardiogram. This type of ultrasound scan can detect the disease even when there are no symptoms that a doctor can notice during a physical examination, a situation referred to as “subclinical rheumatic heart disease”.
In young people, the most common sign of rheumatic heart disease is a leaky mitral valve (mitral regurgitation). Across the world, rheumatic heart disease is the most common cause of a narrowed mitral valve (mitral stenosis). With an echocardiogram, doctors often describe the mitral valve as looking like a ‘dog-leg,’ ‘elbow,’ or ‘hockey-stick’. This simply means that the front part of the mitral valve is thickened and doesn’t move as much as it should.
In 2012, the World Heart Federation came up with criteria to help diagnose rheumatic heart disease using an echocardiogram. The criteria depend on a person’s age. People younger than 20 and those older than 20 have different criteria to evaluate.
The criteria for young people can detect ‘definite’ or ‘borderline’ rheumatic heart disease. Each category has several aspects that doctors look for, such as abnormal blood flow through the heart valves (valve regurgitation), abnormal thickening and motion of the heart valves, or high pressure through a narrowed valve (mitral stenosis).
For people older than 20, the criteria look for a definite diagnosis. This includes similar signs to those in younger people but also includes abnormal aortic valve findings for those under 35 years old.
Again, these features help doctors distinguish a healthy heart from a heart that may be affected by rheumatic disease. By keeping track of these complex features and signs on an echocardiogram, doctors can more accurately diagnose and treat rheumatic heart disease. Each person’s case is unique, and these criteria help doctors make the best decisions for each individual’s care.
Treatment Options for Rheumatic Heart Disease
Managing rheumatic heart disease involves two key areas: prevention and ongoing care. The primary way to prevent rheumatic heart disease is to quickly identify and treat throat infections caused by group A streptococcal bacteria. This helps prevent the occurrence of acute rheumatic fever, a condition linked to rheumatic heart disease. An antibiotic, benzathine penicillin G, is often used to treat these throat infections.
If a patient is diagnosed with acute rheumatic fever, treatment aims to control the body’s inflammatory response to protect the heart and joints from damage. The World Heart Federation suggests that the most economically viable way to prevent the worsening of rheumatic heart disease is secondary prevention. This involves giving penicillin injections every 3 to 4 weeks to prevent repeated group A streptococcal infections that can cause recurrent episodes of acute rheumatic fever, a key factor in rheumatic heart disease progression. However, the ideal duration of this preventative method is not yet known.
A procedure called percutaneous mitral balloon valvuloplasty is a standard first-line treatment for cases of rheumatic mitral stenosis (a narrowing of the heart’s mitral valve). This is applicable if the patient does not experience backflow of blood, irregular heartbeats, or blood clots in the left atrium of the heart. In severe cases of valve disease, which is a common feature of rheumatic heart disease, surgical treatment is often necessary. This surgery could involve either repairing or replacing the affected valve.
If the valve disease causes heart failure, the patient might need to be put on medications, like angiotensin-converting enzyme (ACE) inhibitors, diuretics, and beta-blockers, to manage heart failure symptoms. However, it’s essential to note that there is currently no cure for rheumatic heart disease.
Additionally, doctors should closely monitor patients diagnosed with rheumatic fever and rheumatic heart disease. This allows for the timely start of suitable treatment, contributing to better patient outcomes.
What else can Rheumatic Heart Disease be?
Some conditions that may display similar symptoms to heart disease include:
- Endocarditis, which is an inflammation of the heart’s inner lining
- Functional mitral regurgitation associated with a viral illness such as viral myocarditis, which is an inflammation of the heart muscle
- Mitral valve prolapse due to degenerative myxomatous disease, which is a condition where the heart’s mitral valve doesn’t close tightly
What to expect with Rheumatic Heart Disease
Rheumatic heart disease is a serious condition that claims between 200,000 to 250,000 lives prematurely every year. It’s particularly deadly for children and young adults in countries with limited access to quality medical care.
If the person has a ‘valvular disease’ (a condition where the heart’s valves don’t work properly), it’s very important to monitor this regularly. If not, the disease could progress to a point where severe heart failure can occur. At this advanced stage, surgery might not be an option anymore.
Possible Complications When Diagnosed with Rheumatic Heart Disease
Rheumatic heart disease typically doesn’t show any symptoms until serious complications occur, usually later in life. These complications can include an infection of the heart’s inner lining, a blood clot that occludes a blood vessel, heart failure, high blood pressure in the lungs, and abnormal heart rhythms caused by untreated severe heart valve disease.
Common complications:
- Infection of the heart’s inner lining
- Blockages in a blood vessel due to a clot
- Heart failure
- High blood pressure in the lungs
- Irregular heart rhythms from severe heart valve disease
Preventing Rheumatic Heart Disease
Rheumatic heart disease is quite common in developing countries and is a major cause of heart-related health issues and deaths among young people. According to the guidelines set by the World Health Federation, the best way to prevent rheumatic heart disease is by taking antibiotics, specifically prescribed after diagnosing rheumatic fever.
Patients should be made aware when they have been diagnosed with rheumatic fever. They should also understand the problems that could occur if they do not take their prescribed antibiotics regularly and keep up with their medical appointments. These problems might include valve-related heart diseases, heart failure, and irregular heartbeats—also known as arrhythmias.
