An 8-year-old presents with fever, a migratory polyarthritis, a new pansystolic murmur at the apex, and a rash with central clearing on the trunk. Which of the following is the LEAST reliable indicator for confirming rheumatic carditis?

• A New mitral regurgitation on echocardiography
• B Subcutaneous nodules over bony prominences
• C Prolonged PR interval on ECG (first-degree AV block) ✓
• D Pathological aortic regurgitation on Doppler

Explanation

In the Jones criteria for rheumatic fever, prolonged PR interval (first-degree AV block) is classified as a minor criterion, not a major criterion. While it indicates cardiac involvement, it is the least reliable for confirming carditis since it is non-specific and reversible. New or changing murmurs, echocardiographic evidence of mitral or aortic regurgitation, and subcutaneous nodules (a major criterion) are stronger indicators. Echocardiographic subclinical carditis (pathological regurgitation on Doppler) can now fulfill the carditis criterion per revised Jones criteria.

Reference: Ghai Essential Pediatrics, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.