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