rheumatic heart disease Flashcards
rheumatic heart disease is part of…
rheumatic fever; you must have RF to get RHD
who does RF occur mostly in?
children (5-15 y/o)
in order to get RF, the child must? (2)
- develop strep throat
- have genetic predisposition to RF (about 3% of children—> complex trait)
what normally happens when a child has strep throat?
t-cells and antibodies form and the infection is eradicated by defence cells
in this case what happens when the child has strep?
they are predisposed to molecular mimicry (a form of autoimmunity)—> childs antibodies that were created to eradicate the streptococcus pyogenes (bacteria) begin to attack their self-antigens
autoimmune targeting occurs…
1 week after infection
what happens in this autoimmunity?
antibodies detect the epitope on antigen, abs confused & destroy our own cells
- abs & self-antigen form immune complex that activates complement system….. inflammation and tissue damage (type III abn IR)
- abs that were originally formed to fight against microbe will continue to target Abs even after infection is eradicated
rheumatic fever has… (effects)
systemic effects (abs target antigens in heart, joints, CNS, integument)
where is the infection?
the pharynx (not directly in heart)
why does RF affect the heart?
through AUTOIMMUNITY—> causes systemic effects (infection triggers our own defence cells to destroy our own tissues)
RHD is the effect that RF specifically has on the heart, which is…
inflammation of valves and myocardium and pericardium
acute form of RHD recovery…
self-limiting (heals on its own)
chronic RHD will lead to…
severe heart damage
manifestations of RHD
- general cold/cough symptoms
- valvular dysfunction (d/t inflm near chordae tendinae) resulting in SOBOE, weakness, fatigue, edema, chest pain
diagnosis of RHD?
- first diagnose strep throat (throat swab), however infection may be cleared by RHD symptoms arise
- non-specific tests: CBC, ESR, CRP, differential
