Surgery for Rheumatic Valve Disease Although ARF affects many organs, the main burden of the disease, in terms of morbidity and mortality, stems from chronic heart valve disease.72 The irreversible damage to the valves can be treated by only mechanical methods performed by percutaneous interventions in a small number or cardiac surgery for the majority As described earlier, the indications for and timing of operation are guided by the severity of symptoms, clinical examination, and echocardiographic assessment Cardiac catheterization is seldom required to measure cardiac output and pulmonary vascular resistance The AHA and European Society of Cardiology guidelines55,73 for timing operations in adults are summarized in Table 55.4 and supplemented by pediatric-specific recommendation from the New Zealand national ARF/RHD guidelines.54 Table 55.4 Indications for Valve Intervention ESC/EACTS73 AR Severe symptomatic AR Severe asymptomatic AR if: ■ LVEF 70 mm ■ LVESD >50 mm ■ LVESDI >25 mm/m2 ■ Undergoing other surgery AS Severe symptomatic AS: ■ Mean PG >40 mm Hg ■ Peak velocity >4 m/s Low flow, low gradient severe AS (after careful assessment) Severe asymptomatic if: ■ LVEF 30% Severe asymptomatic MR if: New Zealand Pediatric54 Additions: Additions: Progressive severe LV dilation LVEDD >65 mm if low LVESV zsurgical risk score >4 AHA/ACC55 Additions: ■ Low-dose dobutamine increases severity ■ Resting valve area 45 mm ■ LVEF 50 mm Hg at rest ■ Durable, low-risk repair likely ■ Flail leaflet ■ Significant LA dilation ■ LV dysfunction if repair high likely and low comorbidities MS Severe MS (MVA 50% Surgery if valve not suitable for PMC ■ LVESD >40 mm ■ Severe MR repair is considered with LVEF