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<b>Let's talk about another etiology for valvular disease.</b>
<b>This is rheumatic fever. A rheumatic fever, as you are </b>
<b>probably abundantly aware,</b>
<b>is an acute immunologically mediated multisystem </b>
<b>inflammatory disease</b>
<b>that typically begins, classically, a few weeks after a </b>
<b>group A streptococcal pharyngitis.</b>
<b>So, we're looking into the pharynx of this person,</b>
<b>and we have some angry read mucosa, and we have some </b>
<b>enlarged nodes</b>
<b>and, in this case, would be due to streptococcus </b>
<b>pharyngitis.</b>
<b>The immune response to the strep bacteria</b>
<b>as we will see in the next couple of slides gives rise to </b>
<b>auto - to antibodies that,</b>
<b>for good or for ill in some patients, recognize or </b>
<b>cross-recognize heart antigens,</b>
<b>and that will be the cause of the valvular disease.</b>
<b>You can also have those same antibodies and some of the </b>
<b>inflammatory T cells</b>
<b>can also cause myocarditis or a pericarditis.</b>
<b>So, the systemic manifestations, when you are developing </b>
<b>immune response</b>
<b>to the streptococcal bacteria that caused the pharyngitis,</b>
<b>you can have other manifestations that are part of acute </b>
<b>rheumatic fever. Okay?</b>
<b>It's not just the valvular disease or the carditis that </b>
<b>affects the heart,</b>
<b>you - classically, there are five kind of Jones criteria,</b>
<b>five major manifestations that you need to be thinking </b>
<b>about.</b>
<b>The first one there is subcutaneous nodules typically on </b>
<b>extensor surfaces of the elbows and the knees.</b>
<b>Erythema marginatum which is an irregular kind of somewhat </b>
<b>circular rash</b>
<b>that can be on any body surface.</b>
<b>Sydenham's chorea, this is due to immune complex deposition</b>
<b>or antibodies binding to particular antigens in various </b>
<b>parts of the basal ganglia</b>
<b>and you get patients with kind of uncontrollable </b>
<b>choreoathetoid movements.</b>
<b>There's a polyarthritis. Again, probably immune complex </b>
<b>and/or direct antibody binding.</b>
<b>So, you get a polyarthritis.</b>
<b>And the Jones criteria means that we have evidence of a </b>
<b>preceding group A streptococcal infection,</b>
<b>and then a certain number of the major or minor criteria.</b>
<b>So, on the previous slide were the major criteria.</b>
<b>And then, we have minor criteria that include things</b>
<b>like fever, arthralgia, elevated blood levels of acute phase</b>
<b> reactants.</b>
<b>So, already mentioned this several times,</b>
<b>but now you've heard it probably for the third time, so it's</b>
<b> maybe important.</b>
<b>It does show up on the boards.</b>
<b> About 85% of the time, Rheumatic heart disease is the cause</b>
<b> of mitral stenosis.</b>
<b>And here, you see the valve is thickened, it is somewhat </b>
<b>stenotic,</b>
<b>and the atrium behind it is quite dilated</b>
<b>as a result of the increased pressure having to go through </b>
<b>that tight valve.</b>
<b>The epidemiology of this. So, in developed countries, this </b>
<b>is not a major problem.</b>
<b>That's because we improved sanitation, less streptococcal </b>
<b>distribution within the population,</b>
<b>and also because we have very rapid diagnosis in treatment </b>
<b>of strep pharyngitis</b>
<b>so that we treat with antibiotics before patients develop </b>
<b>any significant antibody titer.</b>
<b>So, overall, in the US, many places in Europe,</b>
<b>there's a declining incidence in mortality from rheumatic </b>
<b>fever and rheumatic heart disease.</b>
<b>On the other hand, in developing countries,</b>
<b>it's still an important public health problem estimated at </b>
<b>15 million people a year</b>
<b>who have some degree of rheumatic heart disease.</b>