Rheumatic heart disease is a sequelae of rheumatic fever which affects heart valves, and can result in heart failure and death if left untreated. It is the most common heart disease acquired by children of developing countries.
occurs after a single or multiple episodes of strep throat
or sore throat
due to group A beta hemolytic streptococci. Antibodies produced by the body against these bacteria react with tissues of the heart and other parts of the body and result in rheumatic heart disease.
The risk of RHD is more with repeated infections of rheumatic fever and in children of 5-15 years of age. Occurrence of RHD is rare before 3 years & after 30 years of age. Treating strep throat infection with antibiotics can prevent rheumatic fever and therefore rheumatic heart disease.
What is the Cause of Rheumatic Heart Disease?
Group A streptococcus is a bacteria that causes throat infection in children
. Following infection, the body produces antibodies as a protective mechanism to fight against the bacteria. However, the antibodies can react with body tissues like heart valves and cause inflammation. The heart valves are located at the opening of the heart chambers and assist in the unidirectional flow of blood. When they are damaged in RHD, they cannot open or shut properly. This affects the blood flow to the body, which results in various symptoms.
The antibodies also target the brain, skin and joints and cause various other associated symptoms.
What are the Risk factors of Rheumatic Heart Disease?
Since rheumatic fever is caused by a communicable disease, the risk factors include:
- Unhygienic living conditions
- Reduced access to medical care
What are the Symptoms & Signs of Rheumatic Heart Disease?
The symptoms and signs of rheumatic heart disease may be:
- Chest pain
- Getting tired easily
- Breathlessness on exertion or while lying down. The patient wakes up from sleep due to breathlessness, stands up and attempts to go to the window or door to get fresh air
- Swelling of the feet
- Fever if the damaged heart valves get infected
In addition, features of rheumatic fever like arthritis
, abnormal movements, subcutaneous nodules and rash may also be present.
Complications of Rheumatic Heart Disease
Complications of rheumatic heart disease include the following:
- Heart failure which ultimately leads to enlargement of the heart (cardiomegaly).
- Infection of damaged heart valves (infective endocarditis). This could result in serious consequence.
- Blood clots may be formed on the damaged heart valves which can break off and travel into blood vessels of the brain thereby cause stroke.
Clinical Types of Rheumatic Heart Disease
RHD mainly affects the mitral, and aortic valves. The other valves may be affected as a secondary consequence to these damages. The mitral valve is at the junction of the left atrium and left ventricle while the aortic valve is at the junction of the left ventricle and the aorta.
Generally, the valvular heart defects are of two types: regurgitation & stenosis. Regurgitation is where there is a backflow of blood while stenosis is where there is an obstruction to the flow of blood. Usually, regurgitation is noted first, and later on, the valve undergoes stenosis.
How to Diagnose Rheumatic Heart Disease?
Rheumatic heart disease is diagnosed if a person meets the criteria for rheumatic fever and the heart is affected. Guidelines for clinical diagnosis of acute rheumatic fever were originally suggested by Dr. Jones and later revised by American Heart Association and the WHO. These are called as JONES criteria.
They consist of major criteria & minor criteria.
For the condition to be diagnosed as rheumatic fever, the presence of two major or one major along with two minor criteria is required, along with evidence that the patient had suffered from a group A streptococcal infection.
- Carditis: This is an early manifestation of rheumatic heart disease. Carditis means inflammation of heart muscle involving all the three layers i.e. pericardium, myocardium & endocardium. Pericarditis causes the chest pain which is one of the symptoms of rheumatic heart disease. Carditis ultimately leads to congestive cardiac failure and enlargement of the heart.
- Arthritis: Arthritis an early manifestation of rheumatic fever. It affects multiple large joints such as knees, ankles & elbows. The affected joints show redness, warmth, swelling, pain and limitation of movement. These symptoms last for 3-7 days and subside on their own, just to appear in some other joint. This condition is called migratory polyarthritis.
- Subcutaneous Nodules: These are late manifestations of the disease. Small swellings appear under the skin on bony prominences like elbow, shin and spine around 6 weeks after the onset of rheumatic fever. They vary in size from pinhead to almond-sized. Patients who have subcutaneous nodules almost always have carditis.
- Chorea: Chorea is anotherlate manifestation of rheumatic fever that occurs 3 months after onset of the fever. Chorea refers to jerky movements resulting in symptoms like deranged speech, muscular incoordination, problems with gait and weakness. Untreated, it resolves on its own in 2-6 weeks.
- Erythema Marginatum: This is an early manifestation of rheumatic fever. It occurs as a faint reddish rash.
- Pain in multiple joints
- Laboratory evidence of infection with increased ESR or white blood cell count
- ECG shows a prolonged P-R interval
Tests that provide evidence of a recent streptococcal infection include an increased or rising anti-streptococcal antibody level, or a positive throat culture or rapid antigen test for group A streptococci. A history of recent scarlet fever is also indicative of streptococcal infection.Approach to diagnosis is done as follows:
- History is taken and if the patient has heart disease and fulfills the necessary criteria, diagnosis tilts towards RHD
- Physical examination may reveal heart murmur, which indicates an abnormality in a heart valve.
- ECG is done to check for enlargement of heart chambers and to detect associated abnormal heart rhythm.
- Echocardiogram is done to check the damage to heart valves and assess the heart failure.
- A throat culture or blood test is done to demonstrate strep infection or antibodies to streptococci respectively.
How is Rheumatic Heart Disease Treated?
Treatment with medications depends on the underlying condition of the patient. Medications like diuretics, digitalis and ACE inhibitors are used to treat heart failure. Surgical treatment depends on the heart valve involved.Rheumatic heart disease with mitral regurgitation (RHD with MR)
Mitral valve repair surgery can be done. Commonest approach nowadays is prosthetic valve replacement, because rheumatic mitral valves are difficult to repair.Rheumatic heart disease with mitral stenosis (RHD with MS)
A procedure called balloon mitral valvotomy (BMV), also known as percutaneous trans-septal mitral commissurotomy (PTMC) is commonly done to treat mitral stenosis
. A catheter with a balloon is introduced into the leg vein up to the mitral valve. Here, the balloon is inflated, which helps to open the valve. The procedure is repeated if stenosis occurs again. Closed mitral valvotomy (CMV) is an inexpensive & equally effective surgical alternative to BMV.Rheumatic heart disease with aortic regurgitation (RHD with AR)
Mild AR usually does not require surgical treatment. Severe AR is treated surgically. The aortic valve is replaced either by homograft or by prosthetic valve. Valve repair is usually not feasible.Rheumatic heart disease with tricuspid regurgitation (RHD with TR)
TR may resolve following mitral valvotomy. If not, tricuspid annuloplasty or repair may be necessary
Prevention of Rheumatic Heart Disease
- Rheumatic heart disease can be prevented by early diagnosis and treatment of strep sore throat and rheumatic fever with penicillin.
- Once a patient has suffered from rheumatic fever, the patient is prescribed long acting benzathine penicillin every 2-4 weeks to prevent a repeated attack. Those allergic to penicillin are given erythromycin.
- Patients with rheumatic fever without carditis receive preventive antibiotics for 5 years after last episode or until they are 21 years old (whichever is longer)
- Patient with carditis but no permanent changes in the valves should receive antibiotics for 10 years or until they are 21 years old (whichever is longer)
- The patients with established RHD should get antibiotics for 10 years after the last attack or until 40 years of age (whichever is longer). In some cases, life-long antibiotics are administered.