Acute rheumatic fever and rheumatic heart disease — branching viva

Opening: recognise and score

The candidate opens by recognising that a school-aged child with a sore throat followed by migratory polyarthritis and a new apical pansystolic murmur has acute rheumatic fever until proven otherwise. The major criteria are the polyarthritis and the clinical carditis. The candidate applies the Jones criteria and identifies that the high-risk criteria apply across all of Australia and New Zealand per the 2020 guideline, so monoarthritis or polyarthralgia may substitute for polyarthritis — though here the full polyarthritis is present. ^{[1] [3]}

The candidate confirms the streptococcal link with antistreptolysin O and anti-DNase B titres, and requests echocardiography to assess the valve and look for subclinical carditis. The candidate names the five major criteria — carditis, polyarthritis, chorea, erythema marginatum, subcutaneous nodules — and the four minor criteria — fever, arthralgia, raised acute-phase reactants, prolonged PR. ^[1]

Branch 1: the 2015 subclinical carditis revision

The examiner probes what changed in the 2015 revision. The candidate explains that Doppler echocardiography is far more sensitive than the stethoscope for detecting valvulitis, so the 2015 revision allows subclinical carditis — pathological valve regurgitation on echo without an audible murmur — to count as a major criterion. A child presenting with polyarthritis and a normal stethoscope but a pathological echo therefore meets two major criteria and has ARF, and the child is committed to the same secondary prophylaxis as the child with an audible murmur. ^[1]

The candidate contrasts this with the pre-2015 era, when subclinical carditis was missed, children were under-diagnosed, and the disease progressed to RHD undetected. The revision reflects the reality that the stethoscope is not sensitive enough in this disease. ^[1]