A 7-year-old child with the rheumatic fever, the following investigations would be needed except

Recommended Tests in Cases of Possible Acute Rheumatic Fever : White blood cell count Erythrocyte sedimentation rate C-reactive protein Blood cultures if febrile Electrocardiogram (if prolonged P-R interval or other rhythm abnormality, repeat in 2 weeks and again at 2 months if still abnormal) Chest x-ray if clinical or echocardiographic evidence of carditis Echocardiogram (consider repeating after 1 month if negative) Throat swab (preferably before giving antibiotics)--culture for group A streptococcus Antistreptococcal serology: both anti-streptolysin O and anti-DNase B titers, if available (repeat 10-14 days later if first test not confirmatory) Ref : Harrison 19th edition pg: 2153