MEDiscuss • Cardiovascular diseases • Rheumatic Fever and Rheumatic Heart Disease
Rheumatic Fever and Rheumatic Heart Disease
i was wondering if anyone had a clear definition of the difference between rheumatic fever and rheumatic heart disease? i understand that RF is an infection and RHD is chronic involving damage to the valves. but it is possible to have RHD and RF at the same time?
Recurrent RF >> RHD
Your basic understanding of the concept of RF and RHD is correct. However, please keep in mind the following:
Rheumatic fever is not direct infection of the cardia. There is Streptococcal infection, away from the heart, generally in the throat, sometimes skin. There is only an immunological cross-reaction between the anti-streptococcal antibodies and proteins in the cardia. This results in cardiac inflammation. The clinical features of this inflammation are labelled "Rheumatic fever".
Have you heard of the saying "Rheumatic fever licks the joint, but bites the heart"? The inflammation is not just in the cardia, but also in the joints. That explains all the symptoms and signs of an acute rheumatic fever.
Most patients recover from this without problems.
Now let's see what happens in the heart after an episode of RF:
Fibrosis: A result of intense inflammation, especially in the endocardial layer. Remember that valves are also covered by a layer of endocardium. This fibrosis also affects the valves therefore. Can this fibrosis result in stenosis? Not yet! Generally one episode does not result in significant permanent changes in the heart.
Now let's look at this: RF usually occurs in persons (esp. children) living in developing countries. This means that they are repeatedly exposed to streptococcal infections. This recurrent infection results in gradually increasing "permanent" damage to the heart by progressive fibrosis. Every episode of acute RF worsens the permanent damage. (that's the reason it bites the heart)
Over a period of time: This results in significant permanent damage which leads to stenosis/ regurgitation lesions in valves, especially mitral. This is called rheumatic heart disease (RHD).
Hope you are getting the concepts further cleared. Remember that recurrent infection is generally the "keyword".
Now, your main question:
Can RF and RHD coexist? YES.
RHD is a chronic valvular heart disease produced by recurrent rheumatic fever. If RF can be recurrent before the onset of RHD, why can't it be afterwards? To give you a comparison, it's like a patient with cirrhosis of liver developing acute hepatitis.
If you have understood the "recurrent RF >> RHD" concept, you will understand why "rheumatic fever prophylaxis" has to be given for a longer duration. That is just to avoid any possibility of streptococcal infection and all related complications as described above.
Now don't confuse RF prophylaxis with IE prophylaxis.
Please do not hesitate to ask if you do not understand any of these clearly.
Thank you so very much. I had never understood this well earlier.
Can you also please explain about the different prophylaxis regimen in patients with RHD?
That's important. I did mention about that in my first reply in this thread...
There are TWO types of prophylaxis given to patients with RHD:
* 1. Rheumatic fever prophylaxis
* 2. Infective endocarditis prophylaxis
1. Rheumatic fever prophylaxis:
As explained above, this is given to all patients who develop an initial episode of rheumatic fever. Aim is to prevent recurrent infection with beta hemolytic streptococci. If not, they may develop recurrent Strep infections and develop RHD.
Therefore: Prevention of Strep. pneumoniae beta hemolytic streptococcal infection >> Prevention of subsequent rheumatic fever >> Prevention of RHD
Classical regimen: Benzathine penicillin IM once in 3-4 weeks.
Duration of prophylaxis: As long as the possibility of beta hemolytic streptococcal infection persists, ideally for life. If this is not practical, at least till the patient is well into middle age.
2. Infective endocarditis prophylaxis
This is different from rheumatic fever prophylaxis. Given to patients with established valvular heart disease (either due to RHD or other causes).
Patients with valvular heart disease are more prone to have bacterial endocarditis. Why? Their valves are abnormal. Whenever there is bacteremia, it is "easy" for the bacteria to "deposit" on the valves and initiate infection - infective endocarditis.
Whenever a patient with a valvular heart disease is likely to have bacteremia - dental extraction, other oral procedures, genitourinary procedures - they are given a course of antibiotics to suppress the bacteremia.
Classical regimen: Oral Amoxycillin for dental procedures. Ampicillin and Gentamycin for genitourinary procedures.
Duration of prophylaxis: Starts about 6 hours before a planned procedure and goes on up to 2 days after the procedure. NOT continuous like rheumatic fever prophylaxis.
If a patient has MDM with OS but no h/o migratory joint pains/sore throat etc, how can we defend our diagnosis of MS likely of rheumatic origin?
This is a very frequent clinical scenario, as only about 50% of patients with RHD give preceding history suggestive of rheumatic fever. It is often difficult to establish the origin of a valvular disease.
Originally Posted by madsapna
In the absence of such a history, the features highly suggestive of rheumatic origin include:
- Stenotic and regurgitant lesions of the same valve
- Involvement of multiple valves
- Calcification of a valve
In addition, pure mitral stenosis is also highly suggestive of rheumatic origin (other causes include systemic lupus erythematosis, rheumatoid arthritis, left atrial myxoma, and infective endocarditis - all these have other suggestive symptoms and signs).
About your direct question about defending the diagnosis of rheumatic origin -
Try to look for features of other causes mentioned above. If none of them are present, you can mention them as excluded and RHD becomes the default etiology. If still in doubt, state the other probable causes as differential diagnosis that makes defending easier for you.
Rheumatic (roo-MAT'ik) heart disease is a condition in which the heart valves are damaged by rheumatic fever.
Rheumatic fever begins with a strep throat (also called strep pharyngitis). Strep throat is caused by Group A Streptococcusbacteria. It is the most common bacterial infection of the throat.
Rheumatic fever is an inflammatory disease. It can affect many of the body's connective tissues — especially those of the heart, joints, brain or skin. Anyone can get acute rheumatic fever, but it usually occurs in children five to 15 years old. The rheumatic heart disease that results can last for life.
The incidence of rheumatic fever/rheumatic heart disease is low in the United States and most other developed countries. However, it continues to be the leading cause of cardiovascular death during the first five decades of life in the developing world.
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