Rheumatic fever/heart disease Flashcards
What is rheumatic fever?
An acute inflammatory disease of the heart potentially involving all layers (endocardium, myocardium and pericardium).
What is rheumatic heart disease?
Is a chronic condition resulting from RF that is characterised by scarring and deformity of the heart valves.
What is the aetiology and pathophysiology of rheumatic fever?
A complication that occurs as a delayed result of a group A streptococcal pharyngitis. Affects the heart, skin, joints, CNS.
What are the signs and symptoms of rheumatic fever?
The presence if two major criteria or one major and two minor criteria plus evidence of a preceding group A streptococcal infection indicates a high probability of RF
Major criteria: carditis is the most important symptom of RF and results in three signs: a heart murmur or murmurs of mitral or aortic regurgitation, or mitral stenosis; cardiac enlargement and HF secondary to myocarditis; pericarditis resulting in muffled heart sounds, chest pain, pericardial friction rub or signs of effusion.
Monoarthritis or polyarthritis is the most common finding in RF. The inflammatory process affects the synovial membranes of the joints, causing swelling, heat, redness, tenderness and limited ROM. The larger joints, particularly the knees, ankles, elbows and wrists are most frequently affected.
Sydenham’s chorea is the major CNS symptom of RF. It is often a delayed sign occurring several months after the initial infection. It is characterised by involuntary movements, especially of the face and limbs; muscle weakness and disturbances of speech and gait.
Erythema marginatum lesions are a less common feature of RF. The bright pink, non-pruitic, map-like lesions occur mainly on the trunk and proximal extremities and may be exacerbated by heat (eg warm bath).
Subcutaneous nodules, usually associated with severe carditis, are firm, small, hard, painless swellings located over extensor surfaces of joints, particularly of the knees, wrists and elbows.
Minor criteria: Evidence of infection: fever, polyarthralgia, increase ESR, increase WBC, increased CRP.
What are the complications of RF?
Chronic rheumatic carditis. It results from changes in valvular structure that may occur months-years after an episode of RF. Rheumatic endocarditis can result in fibrous tissues growth in valve leaflets and chordae tendineae with scaring and contractures. The mitral valve is most frequently involved.
How is RF diagnosed?
Echocardiogram- valvular insufficiency and pericardial fluid or thickening
Chest x-ray- enlarged heart if HF present
ECG change- delayed AB conduction as evidenced by a prolonged PR interval.
Drug therapy- Salicylates, NSAID, steroids