Rheumatic Heart Disease
Rheumatic Heart Disease
Acute rheumatic fever
· Usually affects children/ young adults (5-15 years)
· Most common cause of acquired heart disease in childhood and adolescence
Pathogenesis
· Immune-mediated delayed response to infection with specific strains of group A streptococci, which have antigens that may cross-react with cardiac myosin and sarcolemmal membrane protein
· Antibodies produced à inflammation in the endocardium, myocardium and pericardium, as well as the joints and skin
· Histology
o Fibrinoid degeneration in the collagen of connective tissues
o Aschoff nodules – pathognomonic; occur only in the heart; composed of multinucleated giant cells surrounded by macrophages and T lymphocytes; not seen until the subacute or chronic phases
Diagnosis – Jone’s criteria
2/ more major OR
1 major + 2/ more minor
WITH evidence of preceding streptococcal infection
· Major manifestations
o Carditis - pancarditis
§ Endocardium
§ Myocardium
§ Pericardium
o Polyarthritis – most common; early
o Chorea
o Erythema marginatum
o Subcutaneous nodules
· Minor manifestations
o Fever
o Arthralgia
o Previous rheumatic fever
o Raised ESR or CRP
o Leucocytosis
o First-degree AV block
· Plus supporting evidence of preceding streptococcal infection
o Recent scarlet fever
o Raised antistreptolysin O or other streptococcal antibody titre
o Positive throat culture (only 25% - positive culture d/t latent period between infection, presentation)
In cases of established RHD, a diagnosis of acute RHF can be made with multiple minor criteria + evidence of preceding group A streptococcal pharyngitis
Clinical Features (Duration – acute <6 months; chronic - >6 months)
2-3 weeks after an episode of streptococcal pharyngitis
· Fever
· Anorexia
· Lethargy
· Rashes*- erythema marginatum
o Red macules (blotches) that fade in the centre but remain red at the edges à red margins may coalesce/ overlap
· Joint pain* – flitting polyarthritis + arthralgia
o Painful asymmetrical, migratory inflammation of large joints – knees, ankles, elbows, wrists
o Joints red, swollen and tender for between 1 day and 4 weeks
o Responds to aspirin – characteristic
· Subcutaneous nodules* over bones/ tendons
o Small (0.5-2.0 cm), firm and painless
o Over extensor surfaces of bone or tendons
o Appear more than 3 weeks after the onset of other manifestations
· Carditis*
o Dyspnea (d/t heart failure/ pericardial effusion)
o Chest pain
o Palpitations
o Syncope
o Pericarditis – pain, rub, precordial tenderness
o MR/ AR
o Carey Coombs murmur – soft MDM d/t valvulitis
o Heart block à syncope
o ECG changes – ST, T wave changes
o Tachycardia
o Cardiac enlargement
o Cardiac failure d/t myocardial dysfunction/ valvular regurgitation
· Neurological changes
o Syndenham’s chorea* - St Vitus dance
§ 3 months after acute episode
§ More common in females
§ Emotional lability à purposeless involuntary choreiform movements of the hands, feet or face; explosive/ halting speech
§ Spontaneous recovery within a few months
· Others – pleurisy, pleural effusion, pneumonia
Investigations
· Evidence of a systemic illness (non-specific)
o FBC – leucocytosis
o ESR and CRP – raised; useful to monitor progress
· Evidence of preceding streptococcal infection (specific)
o Throat swab culture: group A β-haemolytic streptococci (also from family members and contacts)
o Antistreptolysin O antibodies (ASO titres): rising titres, or levels of > 200 U (adults) or > 300 U (children)
· Evidence of carditis
o Chest X-ray: cardiomegaly; pulmonary congestion
o ECG: first- and rarely second-degree AV block; features of pericarditis; T-wave inversion; reduction in QRS voltages
o Echocardiography: cardiac dilatation, pericardial effusion and valve abnormalities (MR, MVP, AR)
Treatment
· Bed rest
o Lessens joint pain, reduces cardiac workload
o Duration guided by temperature, WBC count, ESR
o Strenuous activity avoided
· Supportive therapy – cardiac failure
o Medical treatment
o Valve replacement
o Pacemaker insertion – AV block
· Drugs
o Single dose of benzyl penicillin 1.2 million U i.m. or oral phenoxymethylpenicillin 250 mg 6-hourly for 10 days// erythromycin or cephalosporin in penicillin-allergic patients
o Aspirin – arthritis
§ Response within 24 hours – confirms diagnosis
§ Dose: 60mg/kg in 6 doses
§ Adverse effects – nausea, tinnitus, deafness, vomiting, tachypnea, acidosis
§ Continued until ESR has fallen, gradually tailed off
o Corticosteroids – more rapid symptomatic relief in carditis/ severe arthritis
§ Prednisolone 1-2mg/kg/day – until ESR normal, then tailed off
Secondary prevention
· Prevents another episode of acute rheumatic fever, but not infective endocarditis
· Drugs
o Benzathine penicillin 1.2 million U i.m. monthly (if compliance is in doubt) OR
o Oral phenoxymethylpenicillin 250 mg 12-hourly
o (Sulfadiazine or erythromycin – penicillin allergy)
· When to stop? After age of 21 years, unless
o Attack has occurred in last 5 years
o Patient lives in an area with high prevalence
o Patient has an occupation with high exposure to streptococcal infection
· In those with residual heart disease – continue until 10 years after last episode/ 40 years of age, whichever is longer
Chronic rheumatic heart disease
· 50-75% of patients with acute rheumatic fever – progress to CRHD (mostly women) – long term sequelae of ARF
· h/o rheumatic fever/ chorea
· Involvement of heart valves (in order of decreasing frequency)
o Mitral valve
§ MR
§ MS – d/t fusion of mitral valve commisures and shortening of chordae tendineae
o Aortic valve
§ AR
§ AS
o Tricuspid valve
§ TR
§ TS
o Pulmonary valve
· Progressive fibrosis
· Valves predominantly affected; pericardium and myocardium also contribute to heart failure