Rheumatic heart disease Flashcards
What is rheumatic fever?
An acute inflammatory disease of children and young adults caused by infection with pharyngeal strains of Group A beta haemolytic streptococci. RF is due to an autoimmune reaction triggered by molecular mimicry between the M proteins of the infecting streptococci and cardiac myosin and the sarcolemmal membrane protein, laminin. It is also known to occur in persons with high circulating mannose-binding leptin levels and transforming growth factor β1 polymorphisms
How long after initial URTI does RF take to develop?
Approximately 2 weeks
What is the causative orgasnim in Rheumatic fever?
Group A beta haemolytic strep
How does valvular disease occur?
Autoimmune reaction occurs due to cross reaction between carbohydrates in bacterial cell wall and valve tissue.
What is the characteristic lesions in rheumatic fever?
Aschoff nodule - granulomatous lesion composed of an area of central fibrinoid necrosis surrounded by multinucleated giant cells which have elongated nuclei with a distinct chromatin pattern, macrophages and T lymphocytes.
What a clinical features of rheumatic fever?
- Evidence of group A strep infection
- Evidence of carditis
- Arthritis/Arthralgia
- Subcutaneous nodules
- Erythema marginatum
- Sydenham’s chorea
- Fever
What can be features of carditis in rheumatic fever?
- Tachycardia
- Murmurs - Mitra/aortic, carey coombs
- Pericardial rub
- CCF
- Conduction defects
- Cardiomegaly
What may be the only feature of carditis in someone with rheumatic fever?
Apical systolic murmur
What is a carey coombs murmur?
A short, mid-diastolic rumble best heard at the apex, which disappears as the valvulitis improves. It is often associated with an S3 gallop rhythm, and can be distinguished from the diastolic murmur of mitral stenosis by the absence of an opening snap before the murmur.
What is characteristic of the arthritis experienced in rheumatic fever?
Migratory, flitting polyarthritis, which usually affects the larger joints
What are the following?
Subcutaneous nodules - small, mobile, painless nodules on extensor surfaces of joints and spine
What is characteristic of the subcutaneous nodules seen in acute rheumatic fever?
- Small
- Mobile
- Painless
- Extensor surfaces or spine
What is the following?
Erythema marginatum - geographical type rash with red, raised edges and clear centre, occuring mainly on the trunk, thigh or arms
What are the features of erythema marginatum?
- Geographical type rash
- Red
- Raised edges with clear centre
- Occurs mainly trunk, thighs and arms
What is sydenham’s chorea?
https://www.youtube.com/watch?v=tkwzJiikgRk
Unilateral or bilateral involuntary semi-purposeful movements. Described as rapid, arrhythmical, jerky, irregular, non-repetitive, involuntary, and semi-purposive, and disappear during sleep
If someone has syndenham’s chorea, what would this indicate about the chronicity of the rheumatic fever?
Syndenham’s chorea is a late manifestation, occuring 3-6 months after onset of the disease
What can syndenham’s chorea be preceded by?
Emotional lability and uncharacteristic behaviour
What criteria are used to determine if a diagnosis of rheumatic fever can be made?
Revised jones criteria
What are the major criteria of the jones criteria used for diagnosing rheumatic fever?
- Carditis
- Arthritis
- Subcut nodules
- Erythema marginatum
- Syndenham’s chorea
What are the minor criteria of the jones criteria for diagnosing rheumatic fever?
- Fever
- Raised CRP/ESR
- Arthralgia - not if arthritis present
- Prolonged PR interval - not if carditis present
- Previous rheumatic fever
What evidence of group A strp infection is looked for in suspected rheumatic fever?
- Positive throat culture
- Rapid strep antigen test positive
- Elevated/rising strep antibody titre
- Recent scarlet fever
What is the minimum number of major and minor criteria that must be present for the diagnosis of rheumatic fever to be made?
Evidence of group A strep, plus:
- 2 major criteria, or
- 1 major and 2 minor criteria
What investigations might you do in someone with acute rheumatic fever?
- Throat swab
- Bloods - Blood cultures, serology, CRP, ESR, FBC, U+E’s
- Rapid strep antigen test
- ECG
- CXR
- ECHO
What might you see on ECG in someone with rheumatic fever?
- Conduction Defects
- Prolonged PR interval
What might you see on CXR in someone with rheumatic fever?
- Cardiomegaly
- Signs of HF
How would you manage someone with rheumatic fever?
- Bed rest - until CRP returns to normal for 2 wks
-
Analgesia for the carditis/arthritis - aspirin/NSAIDs
- Add steroids if carditis severe
- Penicillin - streptococcal infections
- Valproic acid/Carbemazepine - chorea
- Manage HF
What percentage of those with carditic features of rheumatic fever develop chronic rheuamtic heart disease?
60% - correlates with the severity of the carditis
What is the average time span that an acute episode of rheumatic fever lasts?
3 months
What are the most commonly affected valves in rheumatic heart disease?
- Aortic
- Mitral
- Tricuspid
What sort of valvular abnormality occurs in acute rheumatic fever (stenosis/incompetence)?
Incompetence
What sort of valvular abnormality occurs in chronic rheumatic fever (stenosis/incompetence)?
Stenosis
What changes might be seen on ECG in someone with Rheumatic fever?
- ST and T wave changes
- Reduction in QRS voltages
- Conduction defects
What prophyloactic measures need to be taken in someone who has had rheumatic fever?
Penicillin V, or sulfadiazine
- If carditis + valvular disease - until age 40
- If carditis alone - 10 years
- If no carditis - 5 years
